MathDB
TT2008 Senior O-Level - P3

Source:

September 4, 2010
geometryperimeterperpendicular bisectorgeometry unsolved

Problem Statement

A 3030-gon A1A2A30A_1A_2\cdots A_{30} is inscribed in a circle of radius 22. Prove that one can choose a point BkB_k on the arc AkAk+1A_kA_{k+1} for 1k291 \leq k \leq 29 and a point B30B_{30} on the arc A30A1A_{30}A_1, such that the numerical value of the area of the 6060-gon A1B1A2B2A30B30A_1B_1A_2B_2 \dots A_{30}B_{30} is equal to the numerical value of the perimeter of the original 3030-gon.