Question

Find the sides of the rectangle whose sides are in the ratio 4:5 and perimeter is 90 cm ?

Answer 1

let length =4xcm

breadth= 5xcm

we know perimeter of rectangle= 2(l+b )

90cm = 2(4x+5x)

90= 2(9x)

90=18x

90/18 =x

5=x

•°•length = 4×5= 20cm

breadth = 5×5=25 cm

Answer 2

Given :-

• Sides of rectangle are in the ratio 4 : 5

• Perimeter of rectangle is 90 cm

To find :-

• The sides of the rectangle = ?

Solution :-

Let the length of the rectangle be 4x cm

and breadth of the rectangle be 5x cm

Now,

we know that,

$\orange{\bigstar}\:\:{\underline{\boxed{\bf\pink{Perimeter=2(Length+breadth)}}}}$

$\rm\longrightarrow\:90=2(4x+5x)$

$\rm\longrightarrow\:90=8x+10x$

$\rm\longrightarrow\:90=18x$

$\rm\longrightarrow\:\cancel\dfrac{90}{18}=x$

$\rm\longrightarrow\:5=x$

$\rm\longrightarrow\:x=5$

Now,we have

• 4x = 4 × 5 = 20

• 5x = 5 × 5 = 25

Hence,the sides of the rectangle will be 20 cm and 25 cm.