MathDB
area wanted, 4 equal circles inside a square (2008 VWO Flanders MO p4)

Source:

August 7, 2020
geometrycirclesSqaurearea

Problem Statement

A square with sides 11 and four circles of radius 11 considered each having a vertex of have the square as the center. Find area of the shaded part (see figure). https://cdn.artofproblemsolving.com/attachments/b/6/6e28d94094d69bac13c2702853ac2c906a80a1.png