Question

The perimeter of a rectangle is 20 cm it’s breadth is 4 cn what is its length?

Answer 1

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

given

length = ?

breadth = 4 cm

perimeter = 20 cm

putting on values

20 = 2( l + 4)

20 = 2 l + 8

20 - 8 = 2l

12 = 2l

l = 12/2

length = 6 cm

to verify

2(6+4)

2(10)

= 20 cm

Answer 2

Let the length of the rectangle be l, then

$perimeter = 2(l + b)$

$20 = 2(l + 4)$

$20 = (2l + 8)$

$2l = 20 - 8 = 12$

$l = 12 \div 2 = 6$

ans: 6cm