Question

The length and breadth of a rectangle are in the ratio 3 : 2. If the area is 216 cm², then its perimeter is

(a) 60 cm (b) 30 cm (c) 40 cm (d) 120 cm

Answer 1

Here, l = 3x cm, b = 2x cm and area of rectangle = 216 cm².
Area of rectangle = l $\text{×}$ b = 3x $\text{×}$ 2x = 6x² cm²
As per the question
216 = 6x² $\Rightarrow x^2=36\Rightarrow x=6$
Now
l = 3x = 3 $\text{×}$ 6 = 18 cm
b = 2x = 2 $\text{×}$ 6 = 12 cm
Perimeter of rectangle = 2(l + b) = 2(18 + 12) = 60 cm
Hence, the correct option is (a).