26 In the diagram, $O A B$ is a triangle with $\angle A O B=90^{\circ}$ and $O B=13 \mathrm{~cm} . P \& Q$ are 2 points on $A B$ such that $26 A P=22 P Q=11 Q B$. If the vertical height of $P Q=4 \mathrm{~cm}$, find the area of the triangle $O P Q$ in $\mathrm{cm}^{2}$.
26 Answer: (26)
Note that area of $\triangle O P Q=\frac{1}{2} \times 4 \mathrm{~cm} \times 13 \mathrm{~cm}=26 \mathrm{~cm}^{2}$.