The circumcircle of a polygon is defined: the circle that passes through every vertex.
Math Open Reference

A biography of Euclid. A short description of his life and contributions to the study of geometry. Links to other resources.
Math Open Reference

This page gives two methods for finding the area of a kite: a geometry formula and a trigonometric formula. Numerous connected pages offer a wide variety of information on all types of polygons.
Math Open Reference

A helpful scientific calculator that runs in your web browser window.
Holt Online Learning

A biography of Pythagoras of Samos. A short description of his life and contributions to the study of geometry, including Pythagoras' Theorem. Links to other resources.
Math Open Reference

How to find the area of an irregular polygon by breaking it down into triangles
Math Open Reference

A page with links for properties of circles and different types of polygons. Each link has great visuals with clear markings, definitions, and formulas.
Cool Math

Describes the special relationships of the sides, angles, and diagonals of a rhombus.
Zona Land

A biography of Thales. A short description of his life and contributions to the study of geometry. Links to other resources.
Math Open Reference

Formula and description of the perimeter of a trapezoid.
Math Open Reference
