Square area problem

A, A1, A2, s are defined in question.

Let Area of a SemiCircle, SCA = (PI*s^2)/8.

Let Uneffected area of semicircle, A3 = SCA - 2*A1 (Eq 1).

1/4 of the whole square = A1 + A3,

(s^2)/4 = A1 + A3 (Eq 2).

Simultaneous equation between Eq 1 and 2:

Since A2 = A1 + 2*A3 and A = A1 + A2,

A = 2*A1 + 2*A3,

A = (PI - 2)*(s^2)/4 + (4 - PI)*(s^2)/4,

A = (s^2)/2 (solved!)

math_challenge_#16