Question

the length of rectangle is three times it's width of the perimeter is 84 cm find the number​

Answer 1

Answer:

The length of the rectangle is 31.5 cm and breadth is 10.5 cm.

Step-by-step explanation:

Given :

The length of the rectangle is three times it's width.

Perimeter of the rectangle is 84 cm.

To find :

the number

Solution :

Let the length of the rectangle be l cm and width be b cm.

According to the question,

l = 3b

Perimeter of the rectangle = 2(length + breadth)

84 = 2(l + b)

84 = 2(3b + b)

84 = 2(4b)

84/2 = 4b

42 = 4b

b = 42/4

b = 10.5 cm

The width of the rectangle is 10.5 cm.

Length :

l = 3(10.5)

l = 31.5 cm

The length of the rectangle is 31.5 cm.

Answer 2

Answer:

ஃ Breadth = 10.5 cm

Length = 3x = 3 × 10.5 cm = 31.5 cm

Step-by-step explanation:

Let the breadth be 'x'

Perimeter = 2 ( L + B )

84 cm = 2 ( 3x + x )

2 ( 3x + x ) = 84 cm

2 ( 4x ) = 84 cm

8x = 84 cm

$\sf x = \frac{84}{8} = 10.5 \: cm$