Ab=36(diameter of the circle) Since ap and pb are radius. ap=pb=36/2=18 Then construct a perpendicular line from point C to a point D on the ab. The Ange cpb=30 and angle cup is a right triangle. Then using 30-60-90 rule, 2x=pc=18(it is also a radius) So x=cd=9 And pd=9*root of 3=9root of 3 ad=18+9root of 3 cd=9 Angle cda=90 So according to Pythagoras theorem P²+B²=H² So, ac²=9²+(9 root of 3) I think it will help you.
