MathDB
Determine the angles of triangle PQR

Source:

September 15, 2010
TriangleanglesgeometryIMO ShortlistIMO 1979

Problem Statement

Inside an equilateral triangle ABCABC one constructs points P,QP, Q and RR such that ∠QAB=∠PBA=15∘,∠RBC=∠QCB=20∘,∠PCA=∠RAC=25∘.\angle QAB = \angle PBA = 15^\circ,\\ \angle RBC = \angle QCB = 20^\circ,\\ \angle PCA = \angle RAC = 25^\circ. Determine the angles of triangle PQR.PQR.
Back to ProblemsView on AoPS