Question 182
A trapeze - the figure given represents a trapezoid $ABCD$ where $AB$ is parallel to $CD$ and the diagonals $AC$ and $BD$ is cut at point $P$. If the areas of the triangles $\triangle APB$ and $\triangle CPD$ measure $4$ and $9\ \mathrm{cm}^2$, respectively, what is the area of the triangle $\triangle PCB$? 