Question

The side of a square is increased by $20\%$ . Find the $\%$ change in its area.

• A. $44\%$ increase
• B. $40\%$ increase
• C. No change
• D. None of these

Answer 1

The correct option is A $44\%$ increase

Side is increased by $20\%$

let initial length of side be $x$.

increased length $=x+20\%\left(x\right)$

$=1.2x$

initial area = $x\left(x\right)=x^2$

increased area = $\left(1.2x\right)\left(1.2x\right)=\left(1.44x^2\right)$

percent increase in area= $\frac{1.44x^2-x^2}{x^2}\times 100$

$=0.44\times 100$

percentage increase in are $=44\%$