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.
