Mark (✓) against the correct answer:

(b) 200 cm2

Let $A B C D$ be a quadilateral.

$D$ iagonal, $A C=20 \mathrm{~cm}$

$B L \perp A C$, such that $B L=8.5 \mathrm{~cm}$

$D M \perp A C$, such that $D M=11.5 \mathrm{~cm}$

$A$ rea of the quadilateral $=(A$ rea of $\Delta D A C)+(A$ rea of $\Delta A C B)$

$=\left[\left(\frac{1}{2} \times A C \times D M\right)+\left(\frac{1}{2} \times A C \times B L\right)\right] \mathrm{cm}^{2}$

$=\left[\left(\frac{1}{2} \times 20 \times 11.5\right)+\left(\frac{1}{2} \times 20 \times 8.5\right)\right] \mathrm{cm}^{2}$

$=(85+115) \mathrm{cm}^{2}$

$=200 \mathrm{~cm}^{2}$