ad= bc, distances from a point of circumcircle to lines of inscribed ABCD
Source: 2021 Oral Moscow Geometry Olympiad grades 10-11 p1
May 24, 2021
geometrycircumcirclecyclic quadrilateral
Problem Statement
Quadrilateral is inscribed in a circle, is an arbitrary point of this circle. It is known that distances from point to lines and are equal to and respectively. Prove that .