MathDB
Right Triangle

Source: 1990 IrMO Paper 1 Problem 5

September 30, 2017
geometry

Problem Statement

Let ABCABC be a right-angled triangle with right-angle at AA. Let XX be the foot of the perpendicular from AA to BCBC, and YY the mid-point of XCXC. Let ABAB be extended to DD so that ∣AB∣=∣BD∣|AB|=|BD|. Prove that DXDX is perpendicular to AYAY.
Back to ProblemsView on AoPS