Please help with this geometry question.

Question

CDB is a right triangle inscribed in a circle. D is the right angle at the top of the triangle, touching the top of the circumference of the circle.

Given center A, where arc DB=120 degrees and CD = 8. Determine the exact circumference of the circle.

Answer 1

arc DB = 120°

m∠C = 60º

m∠B = 30º

CB = 2CD

CB = 2(8)

CB = 16

Can you calculate circumference and answer?

Answer 2

Because D is right angle then BC is diametr of circle. Then arc CD = 180° - 120° = 60°.

So, angle B = 30°. Then diametr BC = 16 and circumference equal 16π