The percentage increase in the area of a rectangle, if each of its sides is increased by 20%

Let original length = x metres and original breadth = y metres.

Original area = xy sq.m 

Increased length  =  $\frac{120}{100}$ and Increased breadth =  $\frac{120}{100}$ 

New area =  $\frac{120}{100}x*\frac{120}{100}y=\frac{36}{25}xy m2$ 

The difference between the Original area  and New area  is:  

$\frac{36}{25}xy-xy$

$\frac{11}{25}xy$ Increase % = $\frac{\frac{11}{25}}{x}*100$= 44%