Exercise 3 Page 573

Before we define the lines and segments that intersect a circle, let's first see them on the circle. Visualizing the ways they interact with the circle can help us write the definitions.

Using our diagram, we can define each type of line and segment. Let's do it!

• Chord: A chord is a segment whose endpoints are on a circle.
• Tangent: A tangent is a line in the plane of a circle that intersects the circle in exactly one point.
• Secant: A secant is a line that intersects a circle in two points.
• Radius: A radius is a segment whose endpoints are the center and any point on a circle.
• Diameter: A diameter is a chord that contains the center of the circle.