Explore the angles and arcs of a circle by following these steps.

✓ 1. Move point A to point D and move point B to point F.

The central angle BCA now intercepts the same arc as the inscribed angle FED.

m∠BCA = 1/2 1 2 × m∠FED

✓ 2. Move points D and F until m∠FED equals m∠BCA.

The measure of the arc intercepted by the central angle is 1/2 1 2 times the measure of the arc intercepted by the inscribed angle.