Chapter 1 Activity 4

Chapter 1 Activity 4a

When PQR is moved around the circle, the angle stays the same. When Q moves past R, the angle switches to the the opposite angle. When the radius changes, the angle changes. If the PR is a fixed chord of a circle and Q is a point on that circle, then the measure of PQR is fixed.

1 Activity 4b

The inscribed angle is half of the central angle. If PQR is an inscribed angle of a circle centered at C, then the measure of PQR will be half of the center angle.