Question

The perimeter of the rectangle is $480cm$ and its length is $140cm$. Find its area in square metres.

Answer 1

Step 1: Finding the breadth of the rectangle

Given the perimeter of the rectangle is$480cm$ and its length is $140cm$

The perimeter of the rectangle $=$$2(l+b)$

$$\begin{gathered} 2(140+b)=480 \\ \Rightarrow 140+b=\frac{480}{2} \\ \Rightarrow 140+b=240 \\ \Rightarrow b=240-140 \\ \Rightarrow b=100cm \end{gathered}$$

Step 2: Finding the area of the rectangle:

Area of the rectangle $=$$\mathrm{length}\times \mathrm{breadth}$

$$\begin{gathered} =140\times 100 \\ =14000c{m}^2 \end{gathered}$$

We know that

$$\begin{gathered} 100c{m}^2=1m^2 \\ 14000c{m}^2=140\times 100 \\ 14000c{m}^2=140m^2 \end{gathered}$$

Hence the area of the rectangle is $140m^2.$