MathDB
2021 Geo Div 1 P1 (Div 2 P2)

Source:

March 2, 2021
geometry

Problem Statement

Points AA, BB, and CC lie on a line, in that order, with AB=8AB=8 and BC=2BC=2. BB is rotated 2020^\circ counter-clockwise about AA to a point BB', tracing out an arc R1R_1. CC is then rotated 2020^\circ clockwise about AA to a point CC', tracing out an arc R2R_2. What is the area of the region bounded by arc R1R_1, segment BCB'C, arc R2R_2, and segment CBC'B?
Proposed by Thomas Lam