This is an interesting geometry project that goes back to the time of Archimedes, the famous Greek mathematician. You can combine this mathematical project with computer science and take this ancient problem into the twenty-first century...

[Free Registration/Login may be required to access all resource tools.] This concept teaches students to solve for missing segments created by a tangent line and a secant line intersecting outside a circle.

[Free Registration/Login may be required to access all resource tools.] Find the sine, cosine, and tangent of right triangles.

[Free Registration/Login Required] Students can adjust the size of the circle to explore the tangent lines. Click learn more to watch a video and click challenge me to answer a practice question.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to calculate angles formed outside a circle by tangent and secant lines.

[Free Registration/Login may be required to access all resource tools.] This concept teaches students how to find angles on and inside a circle created by chords and tangent lines.

[Free Registration/Login Required] Students will adjust points to explore secants and tangents of circles. Click learn more to watch a video and click challenge me to answer a practice question.

Guide a mummy safely through the burial chambers of a pyramid as you solve length and area problems in basic to advanced geometry. There are four game zones that deal with circles and triangles, quadrilaterals, the Pythagorean Theorem,...

Provides advanced information about circles through the use of examples and a brief video lesson. [1:00]

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

Discover sine and cosine ratios in trigonometric ratios.

This is a proof problem, considered a "three star" geometry problem requiring knowledge of proofs and properties of circles.

[Free Registration/Login Required] Students identify segments and lines related to circles and the properties of a tangent to a circle.

A wealth of resources to supplement instruction on parts of the circle. Find lessons describing chords, tangents, secants, and segments, as well as related practice quizzes and classroom activities.

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

[Free Registration/Login may be required to access all resource tools.] Solve problems containing angles on or inside a circle.

This resource provides two levels of multiple choice questions to review the parts of a circle as well as area and perimeter.

[Free Registration/Login may be required to access all resource tools.] Name the parts of a circle.

[Free Registration/Login may be required to access all resource tools.] Use the inverse trigonometric ratios.

Rather than dividing a circle into some number of segments (like 360 degrees), mathematicians often prefer to measure angles using the circumference of a unit circle - a circle with radius 1. This way of measuring angles is called...

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

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

[Free Registration/Login may be required to access all resource tools.] This concept teaches students to use inverse trigonometric ratios to solve for missing angles in right triangles.

In Spanish. Interactive activities online on various geometric and trigonometric concepts such as area, perimeter, secants, tangents, etc. A terrific resource for students. Site is organized acoording to shape. (triangle, quadrilaterals,...