Question

Draw parallelogram ABCD with the following measurements and calculate its area.
AB = 8 cm, AC = 10 cm and $\angle$ ABC = ${100}^o$

Answer 1

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

$ar△ABC=\sqrt{s(s-a)(s-b)(s-c)}$

$s=\frac{a+b+c}{2}=\frac{4+8+10}{2}=11cm$

$ar△ABC=\sqrt{11\times 7\times 3\times 1}$

$=15.20c{m}^2$

$\therefore$ Area of parallelogram ABCD$=2\times 15.20=30.40c{m}^2$