A B C D. Refer to the figure. Find BC. 3. 5-Minute Check 4. A B C D. Refer to the figure. Find DE. 13. 5-Minute Check 5. A B C D. Find the length of the radius of the circle. 6.5 in. 5-Minute Check 6.
Identify central angles, major arcs, minor arcs, and semicircles, and find their measures.
congruent arcs—arcs in the same or congruent circles that have the same measure.
adjacent arcs—arcs in a circle that have exactly one endpoint in common.
arc length—the distance between the endpoints along an arc measured in linear units. Since an arc is a portion of a circle, its length is a fraction of the circumference.