Question

the length of a rectangle is 18 cm more than its breadth if the perimeter is 84 cm find the length and breadth​

Answer 1

Step-by-step explanation:

Length = l

Breadth = b

l=18+b

Perimeter = 2(l+b)

84=2(18+b+b)

84/2=18+2b

42-18=2b

24/2=b

12=b

l=18+12

=30

Length =30cm

Breadth =12cm

Answer 2

Answer :-

$\large{\underline{\boxed{\sf Length - 30 cm ; Breadth - 12 cm}}}$

Explanation :-

Given :

• Length of rectangle - 18 cm more than it's breadth
• Perimeter of the rectangle - 84 cm

To find :

The length and Breadth

Solution :

Let the breadth be 'x' cm

and the length be '(x + 18)' cm

We know that,

Perimeter = 2(length + breadth)

According to question,

$\sf\longrightarrow 2(x + x + 18) = 84$

$\sf\longrightarrow 2(2x + 18) = 84$

$\sf\longrightarrow 4x + 36 = 84$

$\sf\longrightarrow 4x = 84 - 36$

$\sf\longrightarrow 4x = 48$

$\sf\longrightarrow x = \dfrac{48}{4}$

$\sf\longrightarrow x = 12$

Hence, the value of x is 12

Now,

Breadth => x = 12 cm

Length => x + 18 = 12 + 18 = 30 cm

Hence, the length is 30 cm and the breadth is 12 cm respectively.