ABCD is a square of side 4. Four equilateral triangles are drawn, outside the square, with each side of the square as the base of one triangle. When the process is completed ABP, BCQ, CDR and DAS are four equilateral triangles. P, Q, R and S lie on a circle O. O is also the center of the square. What is the area of the region that lies inside the circle but outside the square and the triangles?
#SAT #PSAT #ACT