Question

what is the value of d? look at image attached

Answer 1

In a circle, the measure of an inscribed angle is half the measure of the intercepted arc.

∠BCD = arc BAD/2  ⇒ arc BAD = 2*∠BCD = 2*100 = 200°

arc BCD = 360° - arc BAD = 360° - 200° = 160°

∠d = arc BCD/2 = 160/2 = 80°