similar isosceles on sides of convex ABCD, square condition, rhombus wanted
Source: Romania TST 1995 4.4
February 17, 2020
geometryrhombussquareisosceles
Problem Statement
Let be a convex quadrilateral. Suppose that similar isosceles triangles with the bases on the sides of are constructed in the exterior of the quadrilateral such that is a rectangle but not a square. Show that is a rhombus.