# Geometry Calculators

### Angles, Circles, Ellipses, Slope

 Angle Conversion   Calculator for converting seconds, minutes, degrees, mils, grads, radians and revs. Angles In Circles   How to calculate central angles, inscribed angles and angles formed by radii, chords, tangents and secants. This also explains how to calculate angles that are located outside of a circle formed by 2 tangents, 2 secants or a tangent and a secant. 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, this calculates 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.   Tutorial:   Determining a circle's equationKnowing the circle's center and radius OR Knowing 3 points. Ellipses   Calculator and tutorial Slope and Grade Calculator Geometry in the real world. Explains and calculates how to determine a road grade, the pitch of a roof, etc.

### 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. Triangle Height Calculator   Input 3 triangle sides and this calculates all 3 heights all 3 angles and the area. 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.

### Miscellaneous

 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.   Has parallelogram formulas, equations, Heron's formula, etc.

### 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 Spherical Tank Calculator  Calculates tank volume whether it is 0 to 100% full. 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)