VTMO 2026 - Grade 7 - Final - SET 5 - Self-study Question 1

Distinct points $A,B,C$ lie in that order on a straight line. Construct equilateral triangles $ABD$ and $BCE$ on the same side of line $AC$. Let $T$ be the intersection of $AE$ and $DC$. Prove:

a) $TB$ bisects $\angle ATC$.

b) $TA=TB+TD$.