Question

Draw parallelogram $ABCD$ with the following measurements and calculate its area.
$AB=7cm,AC=10cm$ and $\angle$ AOB = ${100}^o$ where $\overline{AC}$ and $\overline{BD}$ intersect at O.

Answer 1

Area of parallelogram ABCD$=2\times ar△ABC$

$ar△ABC=\sqrt{s(s-a)(s-b)(s-c)}$

$s=\frac{a+b+c}{2}=\frac{7+6.4+10}{2}=11.7cm$

$ar△ABC=\sqrt{11.7\times 4.7\times 5.3\times 1.7}=22.25c{m}^2$

$\therefore$ Area of parallelogram ABCD$=2\times 22.25=44.50c{m}^2$