MathDB

angle chasing in a quadrialteral with 3 equal sides, 90^o, 150^o

Source: December 2020 Ukraine Geometry Olympiad VIII p1, IX p1

December 21, 2020

anglesgeometryequal sides

Problem Statement

The three sides of the quadrilateral are equal, the angles between them are equal, respectively

90^o

and

150^o

. Find the smallest angle of this quadrilateral in degrees.