[Free Registration/Login may be required to access all resource tools.] This concept teaches students about tangent lines and how to apply theorems related to tangents of circles.

Solve two challenging problems that apply properties of tangents to find the radius of a circle with a tangent.

Solve problems related to tangents of circles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video or receive hints.

[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.

Solve two problems that apply properties of tangents to determine if a line is tangent to a circle.

Solve two problems that apply properties of tangents to determine if a line is tangent to a circle.

[Free Registration/Login may be required to access all resource tools.] Define the tangent and cotangent graphs using the unit circle.

[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.

This site has many useful formulas and examples relating to circles, including related definitions, circumference of a circle, area of a circle, length of a circular arc, area of a circular sector, equation of a circle in cartesian...

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...

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

[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.] 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.

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

Given examples of circles and the lines that intersect them, the student will use explorations and concrete models to formulate and test conjectures about the properties and relationships among the resulting segments.

The equation of a circle is the focus of this site. Topics include tangents, intersecting circles, and intersection of lines and circles. Examples and a practice test are available.

In this task, students are shown a circle with center O and point P on the circle. L is a line that is a tangent to the circle at P. They must show that line OP is perpendicular to line L. Aligns with G-C.A.2, G-CO.A, and G-CO.C.9.

This task builds on a previous one called ''Right triangles inscribed in circles I.'' Here students are asked to construct a tangent line to a circle from a point outside of the circle. Aligns with G-C.A.4.

Determine the rules for radius and tangents of circles.

This activity is designed to help students discover several important theorems concerning lengths of segments formed by intersecting chords, secants, and tangents.

Solve problems related to tangents of circles.

Generalize that a tangent and a radius form a 90-degree angle.