MathDB
Distinguishing feet of altitudes and bisectors

Source: Sharygin First Round 2013, Problem 12

April 8, 2013
geometryrectanglegeometry proposed

Problem Statement

On each side of triangle ABCABC, two distinct points are marked. It is known that these points are the feet of the altitudes and of the bisectors.
a) Using only a ruler determine which points are the feet of the altitudes and which points are the feet of the bisectors.
b) Solve p.a) drawing only three lines.