Question

The length and breadth of a rectangle are 10 cm and 8 cm respectively. Find its perimeter if the length and breadth are (i) doubled (ii) halved.​

Answer 1

⠀⠀ıllıllı uoᴉʇnloS ıllıllı

$\setlength{\unitlength}{1.0 cm}}\begin{picture}(12,4)\thicklines\put(1,1){\line(1,0){6.5}}\put(1,1.1){\line(1,0){6.5}}\end{picture}$

Length of the rectangle = 10 cm

Breadth of the rectangle = 8 cm

(i) When they are doubled,

⇢l = 10 × 2 = 20 cm

⇢b = 8 × 2 = 16 cm

Perimeter = 2(l + b)

= 2(20 + 16)

= 2 × 36

= 72 cm

(ii) When they are halved,

⇢l = 10/2 = 5 cm

⇢b = 8/2 = 4 cm

Perimeter = 2(l + b)

= 2(5 + 4)

= 2 × 9

= 18 cm

$\setlength{\unitlength}{1.0 cm}}\begin{picture}(12,4)\thicklines\put(1,1){\line(1,0){6.5}}\put(1,1.1){\line(1,0){6.5}}\end{picture}$

Additional Information:

Here,

• L is used for Length.
• B is used for Breadth.

What is Perimeter?

• The the length of the boundary of a closed figure is called the perimeter.

$\setlength{\unitlength}{1.0 cm}}\begin{picture}(12,4)\thicklines\put(1,1){\line(1,0){6.5}}\put(1,1.1){\line(1,0){6.5}}\end{picture}$

Answer 2

Answer:

Length of the rectangle 10 m

Breadth of the rectangle =8 m

Hence, the perimeter of the rectangle is calculated as follows

Perimeter =2(Length+Breadth)

Perimeter =2(10 m+8 m)

=2×18 m

We get,

=36 m

Hence, the perimeter of the rectangle 36 m

Step-by-step explanation: