MathDB

9.1

Part of 1997 All-Russian Olympiad Regional Round

Problems(1)

acute among triangles by reg. 1997-gon - All-Russian MO 1997 Regional (R4) 9.1

Source:

9/23/2024
A regular 19971997-gon is divided into triangles by non-intersecting diagonals. Prove that exactly one of them is acute-angled.
geometrycombinatoricscombinatorial geometryacute