Question

Perimeter of rectangle is 84 cm. If the length of the rectangle is 30 cm, find its breadth.​

Answer 1

Given:length = 30 cm

Perimeter = 84cm

Perimeter of rectangle=2×(l+b)

⇒84=2×(30+b)

⇒42=30+b

∴b=42−30

Hence b=12cm

Hope it helps☺

Answer 2

Correct Question:-

Perimeter of rectangle is 84 cm. If the length of the rectangle is 30 cm, find its breadth.

Given:-

• Perimeter of rectangle = 84 cm
• Length of rectangle = 30 cm

To Find:-

• Breadth of rectangle

Solution:-

$\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\:\: \mathfrak{ \underline{ \green{Formula \: to \: calculate \: the \: perimeter \: of \: rectangle}}}$

$\boxed{ \green{ \star \: \: \: \: { \red{ \mathfrak{ \large{ perimeter = 2(length + breadth)}}}}}}$

According to question,

$\large { \rm \longmapsto \: \: \: \: \: \: \: \: 2(30 + breadth) = 84}$

$\large { \rm \longmapsto \: \: \: \: \: \: \: \: 30 + breadth = \frac{84}{2} }$

$\large { \rm \longmapsto \: \: \: \: \: \: \: \: 30 + breadth = 42}$

$\large { \rm \longmapsto \: \: \: \: \: \: \: \: breadth = 42 - 30}$

$\large { \rm \longmapsto \: \: \: \: \: \: \: \boxed{ \purple{ \mathfrak{breadth = 12 \: cm}}}}$

Hence,

• The breadth of rectangle is 12 cm