Question 29
In the diagram, $ABC$ is a triangle with $AB=39\text{ cm}$, $BC=45\text{ cm}$ and $CA=42\text{ cm}$. The tangents at $A$ and $B$ to its circumcircle meet at $P$. The point $D$ lies on $BC$ such that $PD\parallel AC$. The area of $\triangle ABD$ is $x\text{ cm}^2$. Find $x$.
