Let’s take a rectangle

6.jpg

We know that

In a rectangle, opposite sides are equal

  AB = CD

&  AD = BC

 

Let  

  AB = Length of rectangle = l

  BC = Breadth of rectangle = b

7.jpg

So,

  AB = CD = l

  BC = AD = b

 

 

8.jpg

 

Now,

  Perimeter of rectangle = Sum of all sides

= AB + BC + CD + DA

= l + b + l + b

= 2 l + 2b

= 2 ( l + b)

 

So,

     Perimeter of rectangle = 2 ( l + b)

 

Let’s take some examples

 

Find perimeter of rectangle where length is 15cm & breadth is 9 cm

9.jpg

Given,

  Length = l = 15 cm

  Breadth = b = 9 cm

 

Perimeter of rectangle = 2 × (Length + Breadth)

     = 2 × (15 + 9)

     = 2 × 24

= 48 cm

 

So, perimeter of rectangle is 48 cm

 

Find perimeter of rectangle where length & breadth are 0.5 m & 0.2 m respectively.

Given,

  Length = l = 0.5 cm

  Breadth = b = 0.2 cm

10.jpg

 

Perimeter of rectangle = 2 × (Length + Breadth)

= 2 × (0.5 + 0.2)

= (2 × 0.7)

= 1.4 m

= 1.4 × 100 cm               (1m = 100 cm)

= 140 cm

  1. Chapter 10 Class 6 Mensuration
  2. Concept wise

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.