# Geometry Calculators

### Plane Geometry Calculators

 Angle Conversion Angles In Circles   Tutorial for calculating angles in circles formed from radii, chords, tangents and secants. Calculator for Constructing Regular Polygons Draw a circle, measure the radius and this calculates the length of the polygon's sides. 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. 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 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. 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. Quadrilateral page   Descriptions and graphics discussing 6 different types of quadrilaterals.

### Solid Geometry Calculators

 Area and Volume Calculator for a Sphere or Cylinder The 5 Platonic Solids (Regular Polyhedra) Calculator - Information about the Tetrahedron, Hexahedron (Cube), Octahedron, Dodecahedron, Icosahedron and calculator.