The side of a square is increased from 20cm to 21cm. Calculate the percentage increase in its area
- 2.5%
- 9.3%
- 10.0%
-
10.25%
The correct answer is: D
Explanation
old area = 202 = 400new area = 212 = 441
% increase in area \(=\frac{41}{400}\times \frac{100}{1}\\
=10.25\%\)