[Free Registration/Login may be required to access all resource tools.] This study guide reviews the terminology for circles (tangent, arcs, central angles) and the equation for a circle.

This study guide on circles covers some vocabulary and theorems about segments and lengths. It is available for download with free registration.

Learn about sectors with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.