Circles - Chords and Tangents

Everything Geometry

Circles - Chords and Tangents

Students should be able to:

define chord and tangent.
identify and draw chords and tangents on a circle.

Chords & Tangents

A chord is a line that joins two points on the circle's circumference. A chord that goes through the center is called a diameter.
A tangent is a straight line that just touches a circle. In fact, it only touches the circle at one point. The tangent line is perpendicular to the radius drawn at this point.

Interactive Circle

Use the interactive circle below to draw a chord and a tangent. For the chord, click on the circumference of the circle to make a point and the click on another part of the circumference to draw a chord. Click twice in the same place to draw a tangent.

Click here for a larger version of this mini-movie.