[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.

[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...

[Free Registration/Login may be required to access all resource tools.] Find all angles on the unit circle matching exact trig ratios. Resource includes examples, videos, and practice problems.

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

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

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

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...

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

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.

[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.

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.

Two hands-on lab activities for instructors to use when teaching about the coordinate graphs of the sine, cosine, and tangent functions derived from a unit circle. The graphs of the reciprocals of the three functions are investigated....

The purpose of this task is to use similar triangles and setting up a proportion in order to calculate a side length. Aligns with G-SRT.B.5.

Goes over the equation of a circle, parametric equations of a circle, intersection of circle and line, tangent line in a point of a circle, etc.

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

Students construct chords, secants, and tangents. From those constructions, they develop a deeper understanding of the terms, as well as explore certain properties of the constructions.

Learn about tangents with this handy reference guide. Provides detailed definitions, examples, and an interactive activity that enhances further explanation. Includes links to related topics.

A complete reference guide to circles including parts, angles, and arcs. It provides definitions and interactive activities that enhance further explanation.

The purpose of this task is to apply knowledge about triangles to calculate the sine and cosine of 30 and 60 degrees. Aligns with HSF-TF.A.3.

Take a tour of trigonometry using degrees or radians! Look for patterns in the values and on the graph when you change the value of theta. Compare the graphs of sine, cosine, and tangent.

The free mathematics tutorial explores the unit circle and trigonometric functions. The tutorial consists of definitions and examples with solutions. The interactive applet allows students to investigate domain, range, and asymptotes of...

This applet allows the user to create the graphs of sin, cos, and tan by moving a scroll bar. The user can watch the unit circle and the graph simultaneously to see how the two are related. The user may also choose to see the angle...