MathDB
Iran(3rd round)2009

Source: Problem 1 Geometry

September 13, 2009
geometrygeometric transformationreflectiontrigonometryperpendicular bisectorgeometry unsolved

Problem Statement

1-Let △ABC \triangle ABC be a triangle and (O) (O) its circumcircle. D D is the midpoint of arc BC BC which doesn't contain A A. We draw a circle W W that is tangent internally to (O) (O) at D D and tangent to BC BC.We draw the tangent AT AT from A A to circle W W.P P is taken on AB AB such that AP \equal{} AT.P P and T T are at the same side wrt A A.PROVE \angle APD \equal{} 90^\circ.
Back to ProblemsView on AoPS