⭐ Starlight Tools / Geometry

Geometry Tools

Free browser-based geometry calculators for triangles, circles, polygons, 3D solids, conics, vectors, and coordinate geometry—all private and client-side. Try our Triangle Calculator, Circle Calculator, Cube Calculator, or Vector Calculator.

Geometry Interactive triangle calculator diagram solving sides angles perimeter and area

Interactive Triangle Calculator

Solve any triangle by entering the three values you know. v1.0

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Geometry Trigonometric triangle solver using law of sines and cosines for SAS SSS AAS ASA SSA

Trigonometric Triangle Solver

Law of Sines/Cosines (AAS, ASA, SAS, SSS, SSA) with ambiguous-case handling. v1.0.0

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Geometry Herons formula calculator showing triangle area semiperimeter inradius and circumradius

Heron’s Formula Calculator

Triangle area from three sides. Also shows semiperimeter, inradius, circumradius, altitudes. v1.0.0

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Geometry Pythagorean triples generator listing primitive triples with right triangle diagram

Pythagorean Triples Generator

Generate primitive & scaled triples with live diagram and CSV export. v1.0.0

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Geometry Circle calculator finding radius diameter circumference and area from any value

Circle Calculator

Radius, diameter, circumference, area—solve from any single value. v1.0

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Geometry Ellipse area and perimeter calculator using Ramanujan formulas and elliptic integral

Ellipse Area & Perimeter

Area πab; perimeter via Ramanujan I & II + high-precision elliptic integral. v1.0.0

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Geometry Conic equation finder for circle parabola ellipse hyperbola from points foci or directrix

Conic Equation Finder

Find equations for circles, parabolas, ellipses, hyperbolas from points/foci/directrix. v1.0.0

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Geometry Square calculator diagram solving side diagonal area perimeter and radii

Square Calculator

Solve from side, diagonal, perimeter, area, inradius or circumradius. v1.0.0

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Geometry Rectangle calculator solving width height diagonal perimeter and area

Rectangle Calculator

Find width/height/diagonal/perimeter/area from any two values. v1.0.0

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Geometry Trapezoid calculator for general isosceles and right trapezoids with area height and perimeter

Trapezoid Calculator

General, isosceles, right cases. From bases/legs/height/area/perimeter. v1.0.0

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Geometry Regular polygon calculator for n sided shapes area perimeter apothem and circumradius

Regular Polygon Calculator

Area, perimeter, side, apothem, circumradius, angles for n-gons. v1.0.0

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Geometry Irregular polygon area calculator using shoelace formula with centroid and orientation

Irregular Polygon Area

Shoelace area, perimeter, centroid, orientation; CSV import; self-intersection warnings. v1.0.0

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Geometry Polygon interior and exterior angles calculator showing sum and per vertex values

Polygon Angles Calculator

Sum & per-vertex interior/exterior angles from n or coordinates. v1.0.0

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Geometry Cube calculator diagram computing edge length surface area volume and space diagonal

Cube Calculator

Edge, surface area, volume, space diagonal from any one value. v1.0.0

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Geometry Cylinder calculator for radius diameter height surface area lateral area and volume

Cylinder Calculator

Radius/diameter, height, surface, lateral area, volume from any two. v1.0.0

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Geometry Cone calculator showing height radius slant height surface area and volume outputs

Cone Calculator

Height, radius/diameter, slant height, surface, lateral, volume from any two. v1.0.0

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Geometry Sphere calculator diagram for surface area and volume from radius or diameter

Sphere Calculator

Surface area & volume from radius/diameter. v1.0.0

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Geometry Pyramid calculator for regular bases surface area volume height and slant height

Pyramid Calculator

Surface area, volume, height, slant height for regular pyramids. v1.0.0

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Geometry 2D distance calculator diagram between two coordinate points x1 y1 and x2 y2

2D Distance Calculator

Distance between (x₁,y₁) and (x₂,y₂). v1.0

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Geometry 3D distance calculator showing straight line length between two points in xyz space

3D Distance Calculator

Straight-line distance between two 3D points. v1.0

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Geometry Midpoint calculator plotting the midpoint between two 2D or 3D coordinates

Midpoint Calculator (2D & 3D)

Midpoint between two coordinates; instant visual preview. v1.0.0

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Geometry Slope calculator showing line through two points with slope m angle and equations

Slope Calculator

Slope m, angle, line equations through two points; vertical detection. v1.0.0

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Geometry Line intersection calculator finding crossing point of two lines with parallel detection

Line Intersection Calculator

Intersection of two lines in Ax+By=C or y=mx+b; parallel/coincident detection. v1.0.0

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Geometry Point to line distance calculator showing perpendicular distance from point to line in 2D

Point to Line Distance (2D)

Perpendicular distance from (x₀,y₀) to a line; multiple forms supported. v1.0.0

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Geometry Point to plane distance calculator in 3D showing perpendicular foot and signed distance

Point to Plane Distance (3D)

Compute the perpendicular distance from (x₀,y₀,z₀) to a plane (Ax+By+Cz+D=0, point+normal, or three points). Shows foot of perpendicular and signed/unsigned options. Private, client-side. v1.0.0

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Geometry Plane from three points calculator deriving plane equation and unit normal vector

Plane from 3 Points

Enter three non-collinear points or a point + normal to get Ax+By+Cz+D=0. Includes unit-normal and point–normal forms, plus a friendly 3D viz. Private, client-side. v1.0.0

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Geometry Vector projection and dot cross product calculator showing 2D and 3D vector components

Vector Projection / Dot & Cross

Dot, cross (3D), projection, angle, magnitudes, components. v1.0.0

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Geometry Vector component resolver splitting vectors into components magnitude unit vector and projection

Vector Component Resolver (2D/3D)

Resolve into components, magnitude, unit vector, projection, rejection. v1.0.0

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Geometry Angle between two vectors calculator showing dot product cosine similarity and degrees

Angle Between Two Vectors

θ in degrees/radians, cosine similarity, dot product, magnitudes. v1.0.0

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Geometry Coordinate transformations tool applying translate rotate reflect and scale to 2D points with preview

Coordinate Transformations (2D)

Translate, rotate, reflect, scale one or many points with live preview. v1.0.0

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Geometry 2D rotation matrix calculator building R theta and rotating points about any center

Rotation Matrix Calculator (2D)

Build R(θ) and rotate points about any center; radians/degrees, CW/CCW. v1.0.0

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Geometry Golden ratio calculator splitting a length into phi sections with live diagram

Golden Ratio Calculator

Split any length into golden sections with a live diagram. v1.0.0

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About These Geometry Calculators

These geometry tools solve triangles, circles, polygons, 3D solids, conics, vectors, and coordinate geometry entirely in your browser—no uploads or sign-ups—so homework, teaching, and quick checks stay private.

Popular picks include the Triangle Calculator, Circle Calculator, Cube Calculator, Vector Calculator, and Coordinate Transformations. Use them free anytime.