Question

Can someone help me solve this problem?

Answer 1

 If О is the center of a circle then:

OA = OB = OC = OD [radii]

AB = AH + HB = 15 + 15 = 30  ⇒  AB = CD

So ΔAOB ≅ ΔCOD  [SSS rule] ⇒ x = OH = 16 units.