MathDB
Proving a kite

Source: Serbian JBTST 3, Day 2

May 31, 2009
geometryparallelogramperpendicular bisectorgeometry proposed

Problem Statement

Let ABCD ABCD be a convex quadrilateral, such that \angle CBD\equal{}2\cdot\angle ADB, \angle ABD\equal{}2\cdot\angle CDB and AB\equal{}CB. Prove that quadrilateral ABCD ABCD is a kite.