MathDB
Nice geometry prob is in fact length bash

Source: Romanian NMO 2021 grade 7 P3

April 15, 2023
geometry

Problem Statement

Let ABCABC be a scalene triangle with ∠BAC>90∘\angle BAC>90^\circ. Let DD and EE be two points on the side BCBC such that ∠BAD=∠ACB\angle BAD=\angle ACB and ∠CAE=∠ABC\angle CAE=\angle ABC. The angle-bisector of ∠ACB\angle ACB meets ADAD at NN, If MN∥BCMN\parallel BC, determine ∠(BM,CN)\angle (BM, CN).
Petru Braica
Back to ProblemsView on AoPS