Exercise 12 Page 719

Before determining whether VU is a radius, let's review some important definitions about circles.

• Radius: A segment whose endpoints are the center and any point on the circumference on a circle.
• Chord: A segment whose endpoints are on the circumference of a circle.

Now, consider the given diagram. We can see that the endpoints of VU are on the circumference of the circle.

Therefore, according to the definitions, VU is not a radius, since a radius is a segment which has one endpoint in the center of the circle. Since both endpoints of VU are on the circumference of the circle, it is a chord.