Geometry could be called the study of figures. An overview of the figures found in a typical geometry course contains a study of different triangles, quadrilaterals, and regular polygons. 

A list of geometry definitions and a matching activity.

A complete reference guide to coordinate geometry. It provides definitions and examples that enhance further explanation. Includes links to related topics.

This study guide on lines in a coordinate plane covers key terms, what different line slopes look like, postulates about parallel and perpendicular lines, the slope-intercept equation, how to graph parallel and perpendicular lines, and...

This study guide on Geometry covers some key vocabulary, drawing and labeling diagrams, describing geometric figures, and basic postulates for points, lines, planes, and intersections. It is available for download with free registration.

Learn about planes with this useful reference guide. Provides a detailed definition and examples that enhance further explanation. Includes links to related topics.

This site from Whatis.com provides a great definition of cartesian coordinates. The definition is medium-sized in length and has links to additional information as well.

This encyclopedia entry from Wikipedia offers a discussion on hyperbolic geometry. The site explains how the hyperbolic geometry plane is represented in two dimensions and how lines in the plane must be drawn. Other types of models for...

This study guide on lines and angles covers key terminology; line notation; parallel, perpendicular, and skew lines; and postulates and theorems about lines. It is available for download with free registration.

The tutorial examines basic geometry vocabulary. Definitions and examples of a point, line, line segment, ray, and plane are included.

Looks at the lines of symmetry in different types of polygons. Includes ten practice questions. Each question is accompanied by an explanation of the answer.

[Free Registration/Login may be required to access all resource tools.] Transformations move and modify geometric shapes. There are several types of transformations that all transform figures in different ways. These transformations can...

Explains the terms and symbols used to discuss line angles, what an angle is, and the types of angles. Includes short video lesson demonstrating how to use a protractor to measure an angle. [0:57]

[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.

Explains the basic concept of the area of geometric shapes with step-by-step instructions and methods for solving specific problems on your own relating to this topic.

An extensive discussion of the Elements, which contains all the geometrical knowledge available in the Hellenistic period.

This site from the free encyclopedia, Wikipedia, provides a basic definition for plane of symmetry. Links are given for additional information on related subjects.

A complete reference guide to points, lines, and planes. It provides definitions and interactive activities that enhance further explanation.

Presents biographical information about Rene Descartes (1596-1650), his career, personal life, written works, and his legacy. Covers contributions to philosophy, mathematics, and science.

A comprehensive guide for learning all about plane shapes with definitions and solved examples.

This tutorial provides illustrations for regular 2-D shapes as well as a definition for polygons and for regular polygons.

Offers a look into the mind of Archimedes based on findings within newly discovered manuscript.

A complete reference guide to horizontal lines. It provides definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.

A complete reference guide to points. It provides definitions and an interactive activity that enhances further explanation. Includes links to related topics.