Question

The area of a rectangle is 400 cm which is equal to 25% of the area of a square. What is the side of the square ?

• A. 60 cm
• B. 40 cm
• C. 25 cms
• D. 20 cm

Answer 1

Answer:

B. 40 cm

The side of the square is 40 cm.

1. Find the area of the square

The area of the rectangle (400 $\text{cm}^2$) is equal to 25% (or $\frac{1}{4}$) of the area of the square.
$\text{Area of the square} = \frac{400}{0.25} = 400 \times 4 = 1,600 \text{ cm}^2$

2. Calculate the side length

The area of a square is calculated as $\text{side} \times \text{side}$ (or $\text{side}^2$). To find the side, take the square root of its area.

$\text{Side} = \sqrt{1,600} = 40 \text{ cm}$