MathDB

P4

Part of 2017 Sharygin Geometry Olympiad

Problems(1)

To find angles of the triangle

Source: Sharygin Geometry Olympiad Correspondence Round 2017 P-4 (Grade-8)

5/1/2017
A triangle ABCABC is given. Let C\ensuremath{'} be the vertex of an isosceles triangle ABC\ensuremath{'} with \angle C\ensuremath{'} = 120^{\circ} constructed on the other side of ABAB than CC, and B\ensuremath{'} be the vertex of an equilateral triangle ACB\ensuremath{'} constructed on the same side of ACAC as ABCABC. Let KK be the midpoint of BB\ensuremath{'} Find the angles of triangle KCC\ensuremath{'}. Proposed by A.Zaslavsky
geometry