MathDB

4

Part of 2018 Portugal MO

Problems(1)

symmetrics of circumcenter wrt sides create a congruent triangle

Source: 2018 Portugal p4

10/11/2020
Let [ABC][ABC] be any triangle and let D,ED, E and FF be the symmetrics of the circumcenter wrt the three sides. Prove that the triangles [ABC][ABC] and [DEF][DEF] are congruent. https://cdn.artofproblemsolving.com/attachments/c/6/45bd929dfff87fb8deb09eddb59ef46e0dc0f4.png
geometrycircumcircleSymmetriccongruent triangles