MathDB

1

Part of 2005 India Regional Mathematical Olympiad

Problems(1)

Rhombus

Source: Indian RMO 2005 Problem 1

2/28/2006
Let ABCD be a convex quadrilateral; P,Q, R,S are the midpoints of AB, BC, CD, DA respectively such that triangles AQR, CSP are equilateral. Prove that ABCD is a rhombus. Find its angles.
geometryrhombusparallelogramcomplex numbers