Thread: help this geometry problem

please find the attached problem. Need help to solve it.

(b) Y/4

Imagine it like this...


Here we can clearly see that 4BC makes up the perimeter of the square, Y.

So Y/4 = BC

Consider the unit circle, it's area is pi.

The shaded area would be (1/2) 1 x 1, which is 1/2.

The fraction shaded is:

(1/2)/pi = (1/2) x (1/pi) = 1/(2pi)