Question

The area of parallelogram ABCD is $84c{m}^2$. Calculate the height of parallelogram ABCD and ABEF if AB $=2.1cm.$

Answer 1

$\text{Area of}ABCD=84{\text{cm}}^2$
AB = 2.1 cm
$\text{Then ar}\left(ABCD\right)=AB\times \text{Height of}{\parallel }^{gm}ABCD$
$84=2.1\times h_1$
$\therefore h_1=\frac{84}{2.1}=40cm$
But ar (ABCD) and ar(ABEF) are on the same base and between the same parallels.
$\therefore ar\left(ABCD\right)=ar\left(ABEF\right)$
$ar\left(ABEF\right)=\text{base}\times \text{Height of}{\parallel }^{gm}ABEF$
$84=AB\times \text{height}$
$\therefore \text{height}=\frac{84}{2.1}=40\text{cm}$