Question

12. The length of a rectangle is three times its width and its perimeter 56 m. The length is
(a)7m
(b)14m
(c)21m
(d)28m​

Answer 1

Answer:

Given :-

• Length of rectangle is thrice of breadth.
• Perimeter of rectangle= 56 m.

To Find :-

Length

Solution :-

Let the breadth be 'x' m.

Length = 3 × x = 3x

As we know that

$\tt \: Perimeter = 2(l + b)$

56 = 2(3x + x)

56 = 6x + 2x

56 = 8x

x = 56/8

x = 7 m

Length = 3x = 3(7) = 21 m

$\huge \odot \bf \: Option C$

Answer 2

ANSWER

Let the length of the rectangle be x 

 Breadth  = 3x

Perimeter = 56 m 

2(l+b) = 56 m 

l+b = 28 m 

x+3x = 28 m 

4x = 80 m 

x = 21 m 

length = 21 m Breadth = 7 m