Find a missing right-triangle hypotenuse or leg, plus the completed triangle's area and perimeter.
You enter: Missing side · First known length · Second known length (leg)
Example: 5 units
Open Pythagorean Theorem Calculator →
Calculate a circle's area, circumference, and diameter from its radius.
You enter: Radius
Example: 28.2743338823 square units
Open Circle Area and Circumference Calculator →
Use Heron's formula to calculate triangle area, perimeter, and the altitude to the first side.
You enter: Side a (altitude base) · Side b · Side c
Example: 6 square units
Open Triangle Area from Three Sides →
Calculate floor or panel area, boundary length, and corner-to-corner distance from two sides.
You enter: Length · Width
Example: 48 square units
Open Rectangle Area, Perimeter, and Diagonal →
Analyze two points: slope of the line, distance between them, and their midpoint.
You enter: x1 · y1 · x2 · y2
Example: Slope 0.75; distance 5; midpoint (2, 1.5).
Open Slope, Distance, and Midpoint →
Area of a trapezoid from its two parallel sides and height.
You enter: Parallel side a · Parallel side b · Height (distance between sides)
Example: 16 square units
Open Trapezoid Area →
Volume and surface area of a sphere from its radius.
You enter: Radius
Example: Volume 113.097; surface 113.097 square units.
Open Sphere Volume and Surface Area →
Volume and total surface area of a right circular cylinder.
You enter: Base radius · Height
Example: Volume 62.832; total surface 87.965 square units.
Open Cylinder Volume and Surface Area →
Volume and total surface of a right circular cone.
You enter: Base radius · Vertical height
Example: Volume 37.699; surface 75.398 square units.
Open Cone Volume and Surface Area →
Volume, surface area, and space diagonal of a rectangular box.
You enter: Length · Width · Height
Example: Volume 24; surface 52; diagonal 5.385.
Open Rectangular Box Volume and Diagonal →
Area from base and vertical height plus perimeter from side length.
You enter: Base · Slanted side · Vertical height
Example: Area 24; perimeter 22 square/linear units.
Open Parallelogram Area and Perimeter →
Find the straight-line distance and midpoint between two points on a Cartesian plane.
You enter: Point 1 x · Point 1 y · Point 2 x · Point 2 y
Example: Distance = 5; midpoint = (2.5, 4).
Open 2D Distance and Midpoint Calculator →
Calculate a triangle’s area from its three side lengths and check the triangle inequality.
You enter: Side a · Side b · Side c
Example: Semiperimeter = 6; area = 6 square units; perimeter = 12 units.
Open Heron’s Triangle Area Calculator →
Calculate a circle’s diameter, circumference, and area from its radius.
You enter: Radius
Example: Diameter = 10; circumference ≈ 31.416; area ≈ 78.540 square units.
Open Circle Measurements Calculator →
Calculate the volume, lateral area, and total surface area of a right circular cylinder.
You enter: Radius · Height
Example: Volume ≈ 125.664 cubic units; total surface area ≈ 150.796 square units.
Open Cylinder Volume and Surface Calculator →
Calculate a circular sector’s arc length and area from radius and central angle.
You enter: Radius · Central angle
Example: Arc length ≈ 5.236; sector area ≈ 13.090 square units.
Open Circular Sector Calculator →
Calculate the slant height, volume, and closed surface area of a right circular cone.
You enter: Base radius · Height
Example: Slant height = 5; volume ≈ 37.699 cubic units; total area ≈ 75.398 square units.
Open Cone Volume and Surface Calculator →
Calculate the area of a circular opening from its diameter or radius-equivalent diameter input.
You enter: Aperture diameter
Example: Aperture area ≈ 0.007854 square units.
Open Circular Aperture Area Calculator →
Calculate a compass-style azimuth from east and north coordinate components.
You enter: East component · North component
Example: Azimuth = 45°.
Open Azimuth from East and North Components →
Calculate curved area, total surface area, and volume for a hemisphere from its radius.
You enter: Radius
Example: Curved area ≈ 56.549; total area ≈ 84.823; volume ≈ 56.549 cubic units.
Open Hemisphere Area and Volume Calculator →
Calculate the one-dimensional center of mass for two point masses at entered coordinates.
You enter: Mass 1 · Position 1 · Mass 2 · Position 2
Example: Center of mass = 2 length units.
Open Two-Point Center of Mass Calculator →
Calculate the area of a convex quadrilateral from its two diagonals and the angle between them.
You enter: First diagonal · Second diagonal · Angle between diagonals
Example: Area = 24 square units.
Open Quadrilateral Area from Diagonals Calculator →
Calculate annulus area and cylindrical donut volume from outer radius, inner radius, and height.
You enter: Outer radius · Inner radius · Extrusion height
Example: Area = 21π ≈ 65.973; volume ≈ 65.973 cubic units.
Open Donut and Annulus Geometry Calculator →
Scale a triangle with a supplied similarity factor and calculate the new sides and area ratio.
You enter: Original side A · Original side B · Original side C · Similarity scale factor
Example: New sides = 6, 8, 10; perimeter = 24; area ratio = 4.
Open AAA Triangle Similarity Calculator →
Calculate the area and opposite side of a triangle from two sides and their included angle.
You enter: Side A · Side B · Included angle
Example: Area ≈ 11.249 square units; opposite side ≈ 4.514 units.
Open SAS Triangle Area Calculator →
Classify a valid triangle as equilateral, isosceles, or scalene and as acute, right, or obtuse.
You enter: Side A · Side B · Side C
Example: Scalene right triangle.
Open Triangle Classification by Sides and Angles →
Calculate the straight-line distance between two points in a Cartesian plane.
You enter: First x · First y · Second x · Second y
Example: Distance = 5 units.
Open 2D Euclidean Distance Calculator →
Calculate a circular arc length and sector area from radius and central angle in degrees.
You enter: Radius · Central angle
Example: Arc length ≈15.708; sector area ≈78.540.
Open Circular Arc Length Calculator →
Calculate the area of a triangle from two sides and their included angle.
You enter: Side a · Side b · Included angle
Example: Area ≈29.45 square units.
Open Oblique Triangle Included-Angle Area Calculator →
Calculate the surface area and volume of a sphere from its radius.
You enter: Radius
Example: Surface area ≈314.159; volume ≈523.599 cubic units.
Open Sphere Surface Area and Volume Calculator →
Calculate the area of a triangle from the x and y coordinates of its three vertices.
You enter: Vertex 1 x · Vertex 1 y · Vertex 2 x · Vertex 2 y · Vertex 3 x · Vertex 3 y
Example: Area =15 square units.
Open Coordinate Triangle Area Calculator →
Calculate the average rate of change between two coordinate points.
You enter: First x · First y · Second x · Second y
Example: Average rate of change =2.
Open Average Rate of Change Calculator →
Calculate the centroid coordinates of a triangle from its three vertices.
You enter: Vertex 1 x · Vertex 1 y · Vertex 2 x · Vertex 2 y · Vertex 3 x · Vertex 3 y
Example: Centroid = (2, 1).
Open Coordinate Triangle Centroid Calculator →
Calculate the diagonal, area, and perimeter of a rectangle from its side lengths.
You enter: Width · Height
Example: Diagonal =10; area =48; perimeter =28.
Open Rectangle Diagonal Calculator →
Calculate the area of a trapezoid from its two parallel bases and perpendicular height.
You enter: First parallel base · Second parallel base · Perpendicular height
Example: Area =55 square units.
Open Trapezoid Area Calculator →
Calculate area from a solid’s volume and a perpendicular length, then show the reciprocal volume check.
You enter: Volume · Perpendicular length
Example: Cross-sectional area =12 square units.
Open Cross-Sectional Area from Volume Calculator →
Calculate the perpendicular height of a square pyramid from volume and base side length.
You enter: Pyramid volume · Square base side
Example: Height =12 units.
Open Square Pyramid Height from Volume Calculator →
Compare center travel and spin counts for a coin rolling around the outside or inside of a fixed circle.
You enter: Moving coin radius · Fixed circle radius
Example: Outside center path ≈37.699; outside turns =6; inside path ≈25.133; inside turns =4.
Open Rolling Coin Rotation Paradox Calculator →
Calculate ideal height, arch length, and area for one cycloid arch generated by a rolling circle.
You enter: Generating-circle radius
Example: Height =4; arch length =16; area ≈37.699.
Open Cycloid Arch Geometry Calculator →
Calculate the volume, surface area, and space diagonal of a cube from its side length.
You enter: Cube side length
Example: Volume =27; surface area =54; diagonal ≈5.196.
Open Cube Volume Surface Area and Diagonal Calculator →
Calculate the largest axis-aligned cube side that fits within a cylinder from cylinder radius and height.
You enter: Cylinder radius · Cylinder height
Example: Maximum side =7.0711; cube volume =353.553.
Open Largest Axis-Aligned Cube in a Cylinder Calculator →
Calculate each exterior angle and the total exterior turn of a regular polygon.
You enter: Number of sides n
Example: Each exterior angle =60°; total =360°.
Open Regular Polygon Exterior Angle Calculator →
Calculate the apothem, perimeter, and area of a regular polygon from its side count and side length.
You enter: Number of sides n · Side length
Example: Apothem ≈8.6603; perimeter =60; area ≈259.808.
Open Regular Polygon Area Calculator →
Calculate the volume of a spherical cap from the sphere radius and cap height.
You enter: Sphere radius R · Cap height h
Example: Spherical cap volume ≈435.634.
Open Spherical Cap Volume Calculator →
Calculate the slant height and lateral area of a regular square pyramid.
You enter: Square base side · Vertical height
Example: Slant height =13; lateral area =260.
Open Square Pyramid Slant Height Calculator →
Calculate the area and side length of a rhombus from its perpendicular diagonals.
You enter: Diagonal d₁ · Diagonal d₂
Example: Area =96; side length =10.
Open Rhombus Area from Diagonals Calculator →
Calculate the area of a kite from its perpendicular diagonal lengths.
You enter: Diagonal d₁ · Diagonal d₂
Example: Kite area =63.
Open Kite Area from Diagonals Calculator →
Calculate the circumradius, diameter, and apothem of a regular polygon from its side length and side count.
You enter: Side length · Number of sides
Example: Circumradius =2; apothem ≈1.7321; diameter =4.
Open Circumscribed Circle of a Regular Polygon Calculator →
Calculate the base, lateral, and total surface area of a regular hexagonal pyramid from side length and slant height.
You enter: Hexagon side length · Face slant height
Example: Base area≈41.5692; lateral area=72; total≈113.5692 square units.
Open Regular Hexagonal Pyramid Surface Area Calculator →
Calculate a point on the involute of a circle from its base radius and unwinding angle.
You enter: Base-circle radius · Unwinding angle
Example: x≈11.2782; y≈0.4655 length units.
Open Circle Involute Parametric Point Calculator →
Calculate the area and boundary length of a simple irregular polygon from ordered Cartesian vertices.
You enter: Ordered vertices
Example: Area =31.5; perimeter≈21.8379 coordinate units.
Open Irregular Polygon Area and Perimeter Calculator →
Calculate the lateral area and total surface area of a right trapezoidal prism from its base sides and prism length.
You enter: Trapezoid base 1 · Trapezoid base 2 · Trapezoid leg 1 · Trapezoid leg 2 · Prism length
Example: Base perimeter =20; lateral area =200 square units.
Open Trapezoidal Prism Lateral Area Calculator →
Calculate an ellipse’s semi-latus rectum and full latus-rectum length from semi-major axis and eccentricity.
You enter: Semi-major axis a · Eccentricity e
Example: Semi-latus rectum =6.4; full latus rectum =12.8 units.
Open Ellipse Latus Rectum Calculator →
Build a circle’s center, radius, and Cartesian equation from the two endpoints of a diameter.
You enter: Endpoint 1 x · Endpoint 1 y · Endpoint 2 x · Endpoint 2 y
Example: Center=(1,3); radius=√13; equation=(x−1)²+(y−3)²=13.
Open Circle Equation from Diameter Endpoints Calculator →
Calculate the lateral and total surface area of a right circular conical frustum from its radii and slant height.
You enter: Larger radius R · Smaller radius r · Slant height l
Example: Lateral area=32π≈100.531; total area=66π≈207.345 square units.
Open Conical Frustum Surface Area Calculator →
Find the circumcenter and radius of the unique circle through three non-collinear points.
You enter: Point 1 x · Point 1 y · Point 2 x · Point 2 y · Point 3 x · Point 3 y
Example: Center = (2, 1.5); radius = 2.5.
Open Circle Center from Three Points Calculator →
Compare the corresponding legs of two right triangles and report their scale-ratio difference.
You enter: Triangle 1 leg A · Triangle 1 leg B · Triangle 2 leg A · Triangle 2 leg B · Allowed ratio difference
Example: Both scale ratios are 2; ratio difference = 0%; triangles pass the tolerance check.
Open Right-Triangle Similarity Calculator →
Find the longer and shorter sides and diagonal of a rectangle from its area and perimeter.
You enter: Area · Perimeter
Example: Side lengths are 8 and 6; diagonal = 10.
Open Rectangle Dimensions from Area and Perimeter →
Check three side lengths against the Pythagorean relationship and triangle inequality.
You enter: Side A · Side B · Side C
Example: The sides form a valid right triangle; residual c²−a²−b² = 0.
Open Right Triangle Checker →
Find the area, perimeter, semiperimeter, and inradius of a triangle when all three side lengths are known.
You enter: Side a · Side b · Side c
Example: Area: 6 square units; perimeter: 12 units; inradius: 1 unit.
Open Three-Side Triangle Area Calculator →
Find the centroid of a triangle from the coordinates of its three vertices and report its area.
You enter: Vertex 1 x · Vertex 1 y · Vertex 2 x · Vertex 2 y · Vertex 3 x · Vertex 3 y
Example: Centroid: (2, 1); area: 9 square units.
Open Triangle Centroid Calculator →
Calculate the slant height, base area, lateral area, and total surface area of a right circular cone.
You enter: Base radius · Vertical height
Example: Slant height: 5 units; total surface area: about 75.40 square units.
Open Cone Surface Area Calculator →
Calculate the volume and base area of a right circular cone from its radius and vertical height.
You enter: Base radius · Vertical height
Example: Volume: about 37.70 cubic units; base area: about 28.27 square units.
Open Cone Volume Calculator →
Find the horizontal change, vertical change, straight-line distance, and midpoint between two Cartesian points.
You enter: Point 1 x · Point 1 y · Point 2 x · Point 2 y
Example: Distance: 10 units; midpoint: (4, 6).
Open Coordinate Distance and Midpoint Calculator →
Estimate an ellipse’s perimeter with Ramanujan’s approximation and calculate its area and eccentricity.
You enter: Semi-major axis a · Semi-minor axis b
Example: Perimeter: about 25.53 units; area: about 47.12 square units; eccentricity: 0.80.
Open Ellipse Perimeter and Area Calculator →
Calculate the hypotenuse, area, perimeter, and acute angle of a right triangle from its two legs.
You enter: Leg a · Leg b
Example: Hypotenuse: 5 units; area: 6 square units; angle A: 36.87°.
Open Right-Triangle Hypotenuse Calculator →
Find the height, area, perimeter, and base angles of an isosceles triangle from its equal side and base.
You enter: Equal side length · Base length
Example: Height: 4 units; area: 12 square units; each base angle: 53.13°.
Open Isosceles Triangle Height Calculator →
Calculate a parallelogram’s area from its base and perpendicular height, then report its perimeter from the side length.
You enter: Base length · Perpendicular height · Other side length
Example: Area: 32 square units; perimeter: 26 units.
Open Parallelogram Area and Perimeter Calculator →
Calculate the perimeter, apothem, interior angle, and area of a regular polygon from its side count and side length.
You enter: Number of sides n · Side length
Example: Perimeter: 24 units; apothem: 3.464 units; area: 41.57 square units; interior angle: 120°.
Open Regular Polygon Calculator →
Calculate a rhombus’s area, side length, perimeter, and acute angle from its two diagonals.
You enter: First diagonal · Second diagonal
Example: Area: 24 square units; side: 5 units; perimeter: 20 units; acute angle: 73.74°.
Open Rhombus Area and Perimeter Calculator →
Rotate a Cartesian point about the origin and report its new coordinates, radius, and direction.
You enter: Point x · Point y · Counterclockwise rotation
Example: Rotated point: (-4, 3); radius: 5 units.
Open 2D Point Rotation Calculator →
Find the segment joining the midpoints of a trapezoid’s legs, along with its base average and area.
You enter: Base a · Base b · Perpendicular height
Example: Midsegment: 8 units; base average: 8 units; area: 32 square units.
Open Trapezoid Midsegment Calculator →
Calculate the volume, slant height, lateral area, and total surface area of a right circular truncated cone.
You enter: Larger radius R · Smaller radius r · Vertical height
Example: Volume: about 201.06 cubic units; slant height: about 4.47 units.
Open Truncated Cone Volume Calculator →
Estimate the exact-parametrization surface area and boundary length of a one-half-twist Möbius strip from its centerline radius and half-width.
You enter: Centerline radius · Half-width of strip
Example: The strip has centerline circumference 6.28319 m; the integrated surface area and one continuous boundary length are reported from the parametrized model.
Open Möbius Strip Geometry Calculator →
Calculate the overlap and the two lune-shaped remainder areas formed by two intersecting circles, and identify which lune is a crescent.
You enter: Radius r₁ · Radius r₂ · Center distance d
Example: Overlap ≈ 29.30 square units; lune 1 ≈ 20.96 and is a crescent, while lune 2 ≈ 83.70 and is not.
Open Crescent and Circle-Overlap Area Calculator →
Find the segment joining the midpoints of two triangle sides and verify its parallel-side and scale relationships.
You enter: Parallel triangle side · Second triangle side
Example: midsegment 5 units; linear factor 0.5
Open Triangle Midsegment Calculator →
Recover rectangle length and width from a known perimeter and a chosen length-to-width ratio.
You enter: Perimeter · Length ÷ width ratio
Example: length 12, width 8, area 96
Open Rectangle Dimensions from Perimeter →
Find the second endpoint of a line segment when one endpoint and the midpoint are known, with length and slope checks.
You enter: Known endpoint x₁ · Known endpoint y₁ · Midpoint x-coordinate · Midpoint y-coordinate
Example: Missing endpoint (7, 2), segment length 13.42
Open Find the Missing Endpoint from a Midpoint →
Find the area, diameter, and circumference of a circle from its radius.
You enter: Radius
Example: Area = 78.53981634 square units, diameter = 10 units, and circumference = 31.41592654 units.
Open Area of a Circle Calculator →
Calculate a circle's circumference, radius, and area from its diameter.
You enter: Diameter
Example: Circumference = 31.41592654 units, radius = 5 units, and area = 78.53981634 square units.
Open Circumference Calculator →
Calculate the volume, surface area, face area, and total edge length of a cube.
You enter: Side length
Example: Volume = 64 cubic units, total surface area = 96 square units, and total edge length = 48 units.
Open Cube Volume and Surface Area Calculator →
Calculate the perimeter, apothem, circumradius, area, and interior angle of a regular pentagon from its side length.
You enter: Equal side length
Example: A regular pentagon with 7 length units per side has perimeter 35, apothem about 4.8173, circumradius about 5.9546, and area about 84.3034 square units.
Open Regular Pentagon Calculator →
Calculate the perimeter, apothem, circumradius, area, and interior angle of a regular hexagon from its side length.
You enter: Equal side length
Example: A regular hexagon with 4 length units per side has perimeter 24, apothem about 3.4641, circumradius 4, and area about 41.5692 square units.
Open Regular Hexagon Calculator →
Calculate the perimeter, apothem, circumradius, area, and interior angle of a regular octagon from its side length.
You enter: Equal side length
Example: A regular octagon with 13 length units per side has perimeter 104, apothem about 15.6924, circumradius about 16.9853, and area about 816.0042 square units.
Open Regular Octagon Calculator →
Find every side, area, perimeter, and trigonometric ratio of a 30-60-90 right triangle from any one known side.
You enter: Known side length · Known side
Example: If the short leg is 6, the long leg is about 10.3923, the hypotenuse is 12, the area is about 31.1769, and the perimeter is about 28.3923 length units.
Open 30-60-90 Triangle Calculator →
Find an exact binomial coefficient in Pascal's triangle and the sum of the selected row.
You enter: Row n (top row is 0) · Position k (left entry is 0)
Example: C(5,2) = 10; row sum = 32; the selected entry is the 3rd item in row 5.
Open Pascal's Triangle Entry Calculator →
Count the unit blocks in a stepped square pyramid whose layers have side lengths from one block through the entered base side.
You enter: Base side length
Example: A 5-by-5 base pyramid has 55 blocks: 25 + 16 + 9 + 4 + 1.
Open Square Pyramid Block Count Calculator →
Find the two possible planar intersection points from a baseline and two distances, exposing mirror-image ambiguity and the tangent case.
You enter: Distance between reference points · Distance from point A · Distance from point B
Example: x = 3.6; y = ±4.8; the two possible points are (3.6, 4.8) and (3.6, −4.8).
Open Two-Circle Triangulation Calculator →
Classify a triangle from its three side lengths and calculate its largest angle, perimeter, and semiperimeter.
You enter: Side a · Side b · Side c
Example: Right triangle; largest angle =90°; perimeter =12; semiperimeter =6.
Open Triangle Angle-Type Classifier →
Calculate the area, third side, and altitude of an oblique triangle from two sides and their included obtuse angle.
You enter: First side · Second side · Included angle
Example: Area ≈15.1554 square units; third side ≈10.4403 units; altitude to side a ≈6.0622 units.
Open Oblique Triangle Area Calculator →
Solve for a triangle's base when its area and perpendicular height are known, then verify the area relationship.
You enter: Triangle area · Perpendicular height
Example: Base =12 length units; reconstructed area =30 square units.
Open Triangle Base from Area and Height →
Find the midpoint, coordinate changes, and straight-line length between two points in a Cartesian plane.
You enter: Point 1 x · Point 1 y · Point 2 x · Point 2 y
Example: Midpoint = (4, 6); Δx =6; Δy =8; segment length =10 units.
Open Coordinate Midpoint and Segment Calculator →
Calculate a triangle's area, semiperimeter, perimeter, and inradius from its three side lengths.
You enter: Side a · Side b · Side c
Example: Semiperimeter =6; area =6 square units; perimeter =12; inradius =1 unit.
Open Heron's Formula Triangle Area →
Calculate the area, perimeter, height, inradius, and circumradius of an equilateral triangle from its side length.
You enter: Equal side length
Example: Area ≈15.5885 square units; perimeter =18; height ≈5.1962; inradius ≈1.7321; circumradius ≈3.4641.
Open Equilateral Triangle Geometry Calculator →
Calculate the area, perimeter, apothem, circumradius, and interior angle of a regular decagon from its side length.
You enter: Equal side length
Example: Area ≈192.3552 square units; perimeter =50; apothem ≈7.6942; circumradius ≈8.0902; interior angle =144°.
Open Regular Decagon Area and Geometry →
Calculate the area, perimeter, apothem, circumradius, and interior angle of a regular dodecagon from its side length.
You enter: Equal side length
Example: Area ≈179.1384 square units; perimeter =48; apothem ≈7.4641; circumradius ≈7.7274; interior angle =150°.
Open Regular Dodecagon Area and Geometry →
Calculate the area, perimeter, apothem, circumradius, and interior angle of a regular heptagon from its side length.
You enter: Equal side length
Example: Area ≈130.8208 square units; perimeter =42; apothem ≈6.2296; circumradius ≈6.9143; interior angle ≈128.5714°.
Open Regular Heptagon Area and Geometry →
Calculate the base area, volume, perimeter, apothem, and slant height of a regular hexagonal pyramid from its side and vertical height.
You enter: Base side length · Vertical height
Example: Base area ≈41.5692 square units; volume ≈124.7077 cubic units; base perimeter =24; slant height ≈9.6437 length units.
Open Regular Hexagonal Pyramid Volume Calculator →
Solve a missing side segment when a line parallel to a triangle base creates two proportional smaller sides.
You enter: Upper left segment · Lower left segment · Upper right segment
Example: Lower-right segment =7.5; full left side =10; full right side =12.5; scale factor =2.5.
Open Triangle Proportionality Theorem Calculator →
Compare two triangles by their three side lengths, test SSS congruence, and compare perimeter and area.
You enter: Triangle 1 side a · Triangle 1 side b · Triangle 1 side c · Triangle 2 side a · Triangle 2 side b · Triangle 2 side c
Example: Congruent by side lengths; both perimeters =12 and both areas =6 square units.
Open Triangle Congruence by Side Lengths →
Calculate a triangle's linear scale factor and project how its perimeter and area change under a similar enlargement or reduction.
You enter: Source corresponding length · Target corresponding length · Source perimeter · Source area
Example: Scale factor =1.5; target perimeter =36; target area =67.5 square units; area change =125%.
Open Triangle Scale Factor and Area Change →
Calculate the volume of a right trapezoidal prism from its two parallel bases, trapezoid height, and prism length.
You enter: First parallel base · Second parallel base · Trapezoid perpendicular height · Prism length
Example: Trapezoid base area = 26 square units; prism volume = 260 cubic units.
Open Trapezoidal Prism Volume Calculator →
Calculate surface area, volume, and their ratio for a cube, sphere, or right circular cylinder.
You enter: Shape model · Side or radius · Cylinder height (ignored for cube or sphere)
Example: For a cube of side 4, surface area = 96 square units, volume = 64 cubic units, and SA/V = 1.5 per length unit.
Open Surface Area to Volume Ratio Calculator →
Check whether three positive lengths can form a non-degenerate triangle, show every inequality slack, and calculate Heron area when valid.
You enter: Side a · Side b · Side c
Example: The sides form a valid triangle; the three slacks are 6, 4, and 2, and Heron area is 6 square units.
Open Triangle Inequality Calculator →
Arc length and sector area from a radius and central angle in degrees or radians.
You enter: Radius · Central angle · Angle unit
Example: Arc length 5.236; sector area 13.09.
Open Circular Arc Length and Sector Area →
Area enclosed by an ellipse from its semi-major and semi-minor axes.
You enter: Semi-axis a · Semi-axis b
Example: Ellipse area 47.12.
Open Ellipse Area →
Area of a regular n-gon from side count and side length.
You enter: Number of sides · Side length
Example: 41.569 square units.
Open Regular Polygon Area →
Calculate a hemisphere's volume, curved surface area, and total surface area from its radius.
You enter: Radius
Example: Volume 56.548668; curved area 56.548668; total area 84.823002 square units.
Open Hemisphere Geometry →
Calculate the volume of an ellipsoid from its three semi-axis lengths.
You enter: Semi-axis a · Semi-axis b · Semi-axis c
Example: Ellipsoid volume 100.530965 cubic units.
Open Ellipsoid Volume →
Calculate the volume of a pyramid from its base area and perpendicular height.
You enter: Base area · Perpendicular height
Example: Pyramid volume 120 cubic units.
Open Pyramid Volume →
Calculate the volume of a right circular frustum from its two radii and perpendicular height.
You enter: Larger radius R · Smaller radius r · Perpendicular height
Example: Frustum volume 205.250254 cubic units.
Open Conical Frustum Volume →
Calculate the area, curved arc length, and full perimeter of a semicircle from its radius.
You enter: Radius
Example: Area 39.269908; arc length 15.707963; perimeter 25.707963.
Open Semicircle Geometry →
Calculate the area of a kite from the lengths of its perpendicular diagonals.
You enter: Diagonal 1 · Diagonal 2
Example: Kite area 30 square units.
Open Kite Area →
Calculate a triangle's area and orientation from the Cartesian coordinates of its three vertices.
You enter: Point 1 x · Point 1 y · Point 2 x · Point 2 y · Point 3 x · Point 3 y
Example: Triangle area 6 square units; orientation counterclockwise.
Open Coordinate Triangle Area →
Calculate a triangle's area from two sides and their included angle.
You enter: Side a · Side b · Included angle
Example: SAS triangle area 8.75 square units.
Open SAS Triangle Area →
Find the centroid of a triangle from the Cartesian coordinates of its three vertices.
You enter: Point 1 x · Point 1 y · Point 2 x · Point 2 y · Point 3 x · Point 3 y
Example: Centroid (2, 2).
Open Triangle Centroid →
Calculate the volume of a parallelepiped from three edge vectors.
You enter: Vector A x · Vector A y · Vector A z · Vector B x · Vector B y · Vector B z · Vector C x · Vector C y · Vector C z
Example: Parallelepiped volume is 24 cubic units.
Open Volume of a Parallelepiped →
List integer right-triangle side triples up to a selected hypotenuse limit.
You enter: Maximum hypotenuse · Triple set
Example: There are 11 triples with hypotenuse at most 30.
Open Pythagorean Triples →
Find the Cartesian circumcenter and circumradius of a non-collinear triangle from its three ordered vertices.
You enter: Vertex A x1 · Vertex A y1 · Vertex B x2 · Vertex B y2 · Vertex C x3 · Vertex C y3
Example: The circumcenter is (2, 1.5) and the circumradius is 2.5.
Open Circumcenter of a 2D Triangle →
Find the Cartesian orthocenter of a non-collinear triangle from its three ordered vertices.
You enter: Vertex A x1 · Vertex A y1 · Vertex B x2 · Vertex B y2 · Vertex C x3 · Vertex C y3
Example: The orthocenter is (0, 0), the right-angle vertex.
Open Orthocenter of a 2D Triangle →
Calculate the straight-line Euclidean distance between two ordered points in a three-dimensional Cartesian coordinate system.
You enter: Point 1 x · Point 1 y · Point 1 z · Point 2 x · Point 2 y · Point 2 z
Example: Differences are (3, 4, 12), so the Euclidean distance is sqrt(9 + 16 + 144) = 13 coordinate units.
Open 3D Euclidean Distance →
Find the straight chord length determined by a circle radius and a minor central angle measured in degrees.
You enter: Circle radius · Minor central angle
Example: A radius of 5 and a 60-degree central angle give c = 2 x 5 x sin(30 degrees) = 5 length units.
Open Circle Chord Length →
Calculate the shortest spherical-surface distance and central angle between two latitude-longitude points on a sphere.
You enter: Sphere radius · Point 1 latitude · Point 1 longitude · Point 2 latitude · Point 2 longitude
Example: The central angle is pi/2 radians and the quarter-sphere distance is 6371 x pi/2 = about 10007.543 distance units.
Open Great-Circle Distance →
Calculate the volume of a non-self-intersecting ring torus from its major radius and smaller tube radius.
You enter: Major radius R · Minor radius r
Example: V = 2 pi^2 x 5 x 2^2 = 40 pi^2, approximately 394.784 cubic length units.
Open Ring Torus Volume →
Add the two parallel bases and two legs of a nondegenerate convex trapezoid after checking that the four lengths can form the shape.
You enter: Parallel base 1 · Parallel base 2 · Leg 1 · Leg 2
Example: The bases differ by 2, the legs satisfy the shape check, and P = 5 + 3 + 4 + 4 = 16 length units.
Open Convex Trapezoid Perimeter →
Calculate one interior angle of a regular polygon from its whole-number count of sides.
You enter: Number of sides n
Example: A regular hexagon has angle ((6 - 2) x 180) / 6 = 120 degrees.
Open Regular Polygon Interior Angle →
Calculate the area between a circle chord and its minor arc from radius and included central angle.
You enter: Circle radius · Minor central angle
Example: theta = pi/3 radians, so A = 1/2 x 25 x (pi/3 - sin(pi/3)) = about 2.26465 square length units.
Open Minor Circular Segment Area →
Construct the standard axis-aligned ellipse equation from a center and positive horizontal and vertical semiaxes.
You enter: Center h · Center k · Horizontal semiaxis a · Vertical semiaxis b
Example: The standard equation is (x-2)^2/25 + (y+3)^2/4 = 1, with horizontal semiaxis 5 and vertical semiaxis 2.
Open Ellipse Standard Form →
Find the focal distance, horizontal foci, and eccentricity from an ellipse center, semimajor axis, and semiminor axis.
You enter: Center h · Center k · Semimajor axis a · Semiminor axis b
Example: c=sqrt(25-16)=3, so the foci are (-1,3) and (5,3), focus separation is 6, and eccentricity is 0.6.
Open Foci of an Ellipse →
Estimate the circumference of an ellipse with the clearly labeled Ramanujan II approximation and its shape parameter.
You enter: Semiaxis a · Semiaxis b
Example: h=((5-3)/(5+3))^2=0.0625; Ramanujan II gives an approximate circumference of 25.52699886 length units.
Open Ellipse Circumference Approximation →
Convert Cartesian x, y, z coordinates to cylindrical rho, normalized azimuth, and unchanged z.
You enter: Cartesian x · Cartesian y · Cartesian z
Example: rho=sqrt(1^2+1^2)=sqrt(2), azimuth=45 degrees, and cylindrical z remains 3 coordinate units.
Open Cylindrical Coordinates →
Calculate the material volume of a uniform hollow cylinder from outer radius, inner radius, and height.
You enter: Outer radius R · Inner radius r · Height h
Example: Annular area is pi(25-4)=21pi square units, so material volume is 210pi, approximately 659.734457 cubic units.
Open Hollow Cylinder Volume →
Calculate the surface area of an ordinary ring torus from its major and minor radii.
You enter: Major radius R · Minor radius r
Example: S=4pi^2(5)(2)=40pi^2, approximately 394.784176 square units.
Open Torus Surface Area →
Find the perpendicular height implied by two parallel bases and a positive trapezoid area.
You enter: Parallel base 1 b1 · Parallel base 2 b2 · Trapezoid area A
Example: h=2(39)/(8+5)=78/13=6 length units.
Open Trapezoid Height →
Calculate the perimeter of a regular polygon from an integral side count and common side length.
You enter: Number of sides n · Common side length s
Example: A regular hexagon has P=6*4=24 length units.
Open Regular Polygon Perimeter →
Calculate the total surface area of a straight triangular prism from three valid base sides and prism length.
You enter: Triangle side a · Triangle side b · Triangle side c · Prism length L
Example: The 3-4-5 base has area 6 and perimeter 12, so total surface area is 2(6)+12(10)=132 square units.
Open Surface Area of a Triangular Prism →
Calculate the volume of a regular tetrahedron from its common edge length.
You enter: Common edge length a
Example: V=6^3/(6sqrt(2))=36/sqrt(2)=18sqrt(2), approximately 25.455844 cubic units.
Open Regular Tetrahedron Volume →