MathNet 2019-part-01 — 184 problems (EN–VI) Question 16

In triangle $ABC$ we have $A\hat{C}B = 2 \cdot A\hat{B}C$. Moreover, $P$ is a point inside triangle $ABC$ such that $AP = AC$ and $PB = PC$. Prove that $B\hat{A}C = 3 \cdot B\hat{A}P$.