If each side of square is increased by 20% then find the percentage change in its area.

If each side of square is increased by 20% then find the percentage change in its area.

New Side Length = Original Side Length × (1 + Percentage Increase)

New Area = (New Side Length)²

Percentage Change in Area = $$\frac{\text { NewArea }- \text { OriginalArea }}{\text { OriginalArea }} \times 100$$​​

Let original side length = a

New Side Length = a × (1 + 0.20) = 1.2a

Original Area = a²

New Area = (1.2a)²= 1.44a²

Percentage Change in Area = $$\frac{1.44 a^2-a^2}{a^2} \times 100$$​

$$\begin{aligned}& \Rightarrow \frac{0.44 a^2}{a^2} \times 100 \\& \Rightarrow 0.44 \times 100 \\& \Rightarrow 44 \%\end{aligned}$$ 

Thus, the correct answer is (B).​