Question

In parallelogram ABCD, AB = 16 cm, BC = 12 cm and diagonal AC = 20 cm. Find the area of the parallelogram ABCD.

• A. $96c{m}^2$
• B. $126c{m}^2$
• C. $112c{m}^2$
• D. $192c{m}^2$

Answer 1

The correct option is D

$192c{m}^2$

s = $\frac{20+12+16}{2}$.
$=24$

Area of $\Delta$ ABC $=\sqrt{s(s-a)(s-b)(s-c)}$

$\Delta =\sqrt{24(24-20)(24-12)(24-16)}$.
$=96c{m}^2$

Area of parallelogram = 2 $\times$ $\Delta ABC$

= 2 $\times$ 96

= 192 $c{m}^2$