Triangle BCD is isosceles and BC ≅ BD. Circle A is shown. Isosceles triangle C B D has points on the circle. The lengths of C B and B C are congruent. The measure of arc C D is 100 degrees. What is the measure of Arc B C? 100° 120° 130° 160°

Areflection of shape i across the y-axis, followed by a , and then a translation left 6 units and down 4 units confirms congruence between shape i and shape ii. alternatively, a of shape ii about the origin, followed by a reflection across the y-axis, and then a translation right 4 units and up 6 units confirms congruence between shape ii and shape i.