black area by 6 arcs of radius = circle radius (1995 Chile Level 2 P2)
Source:
August 29, 2019
geometryarcareascircle
Problem Statement
In a circle of radius , six arcs of radius are drawn, which cut the circle as in the figure. Determine the black area.
https://cdn.artofproblemsolving.com/attachments/8/9/0323935be8406ea0c452b3c8417a8148c977e3.jpg