# Ex.11.1 Q2 Perimeter and Area - NCERT Maths Class 7

## Question

Find the area of a square park whose perimeter is \(320\,\rm{} m.\)

## Text Solution

**What is known?**

Perimeter of a square park.

**What is the unknown?**

The area of a square park.

**Reasoning:**

In this question, perimeter of square park is given. By using the fact that the perimeter of square is equal to the sum of all the sides, we can find out the sides of square. Once the value of sides are known, the area of square can be easily obtained.

**Steps:**

Given,

Perimeter of square park \(= 320\,\rm{}m\)

Let length of each side of the square be \(a\)

\[\begin{align}\text{Perimeter} &= \text{Sum of all the sides}\\320\,\rm m&= a + a + a + a\\4a &= 320 \, \rm m\\a &= 80\;\rm{m}\end{align}\]

So, \(a = 80\,\rm{}m\)

\[\begin{align}\therefore{\text{Area of square}}&= {\text{side}} \times {\rm{side}}\\ &= 80 \times 80{\rm{ }}\\ &= 6400{\rm{ }}{\rm \,m^2}\end{align}\]