# Geometry Calculators

### Plane Geometry Calculators

 ANGLES, CIRCLES, ELLIPSES Angles In Circles   Tutorial for calculating angles in circles (central angles, inscribed angles, etc.) formed from radii, chords, tangents and secants. Central Angle Calculator   Calculates a Circle's Central Angle, Radius or Arc Length CIRCLE Calculator   for Radius, Central Angle, Chord, Segment Height, Apothem, Arc Length and Chord Length. If you know two, it will calculate the other five as well as the Sector Area, Segment Area and Circle Area.   ARC to CHORD RATIOS   a listing from 1° to 180° Circle Equation Tutorial Explains equations of the type x² + y² = r² Circle Equation Calculator Input 3 points and it calculates a circle's center radius and equation. Ellipses   Calculator and tutorial TRIANGLE   CALCULATORS Types of Triangles   A chart showing triangles classified by angles (acute, right, obtuse) and by sides (equilateral, isosceles, scalene). Also has triangle area formulas and a triangle area calculator. Triangle Centers   A tutorial discussing the incenter, circumcenter, centroid, orthocenter and the Euler line. Triangle Tester   Calculates if 3 sides will form a triangle or not. Triangle Tester   Input 3 triangle side lengths and this calculates if the sides will form an equilateral, isosceles, acute, right or obtuse triangle. Ultimate Triangle Calculator   Input 3 triangle sides, 2 sides with the included angle or 2 angles with the included side and this calculates all the other triangle information. Side Side Angle Triangle Calculator   If you know 2 triangle sides and a non-included angle, this calculates the other side and the other 2 angles. QUADRILATERAL   CALCULATORS Quadrilateral page   Descriptions and graphics discussing 6 different types of quadrilaterals. Rhombus Calculator   Input side length and either angle and it calculates the area, both diagonals, altitude, perimeter.   Input both diagonals and it calculates the side, area, altitude, perimeter and both angles. Calculator for Parallelograms   Input two parallelogram sides and one angle and it calculates the area, both diagonals, altitude, perimeter and the angle of intersection of the diagonals.   Input both diagonals and diagonal intersection angle and it calculates area, both sides, altitude, height, perimeter and both angles. POLYGON   CALCULATORS Regular Polygon Calculator   Input the number of sides and the side length and it calculates the polygon perimeter, all angles (interior, central and exterior), the inradius, the circumradius and the total area. Calculator for Constructing Regular Polygons Draw a circle, measure the radius and this calculates the length of the polygon's sides.   Polygons that have integer angles.   A listing of the 22 Regular Polygons whose angles are integers.

### Solid Geometry Calculators

 Area and Volume Calculator for a Sphere or Cylinder Triangular Prism Calculator - Input the 3 triangle sides, the height and it calculates the total area and volume. Rectangular Solid (Rectangular Prism) - Calculates Area and Volume The 5 Platonic Solids (Regular Polyhedra) Calculator - Information about the Tetrahedron, Hexahedron (Cube), Octahedron, Dodecahedron, Icosahedron and calculator.   Also explains Euler's Polyhedron Formula:   (V -E +F = 2)