Question

Find the peremeter of rectangle of brendth 3 cm, whose area is equal to the area of a square of side 9 cm
​

Answer 1

Required Answer :

The perimeter of rectangle = 60 cm

Given :

• Area of rectangle is equal to the area of square.
• Breadth of rectangle = 3 cm
• Side of square = 9 cm

To find :

Firstly, we will calculate the area of square.

Using formula,

• Area of square = a²

where,

• a denotes the side of square

Substituting the given values :

→ Area of square = (9)²

→ Area of square = 81

Area of the square = 81 cm²

Area of rectangle = Area of square

→ Area of rectangle = 81 cm²

Using formula,

• Area of rectangle = l × b

where,

• l denotes the length
• b denotes the breadth

Substituting the given values :

→ 81 = l × 3

→ 81/3 = l

→ 27 = l

Length of the rectangle = 27 cm

Using formula,

• Perimeter of rectangle = 2(l + b)

Substituting the given values :

→ Perimeter of rectangle = 2(27 + 3)

→ Perimeter of rectangle = 2(30)

→ Perimeter of rectangle = 60

Therefore,

• The perimeter of rectangle = 60 cm

Answer 2

Given:

• Breadth of rectangle = 3 cm
• Area of rectangle = Area of square
• Side of square = 9cm

To Find:

• Perimeter of rectangle

Solution:

Side of square = 9cm

Area of square = 9 × 9

Area of square = 81 cm sq

We know that,

Area of rectangle = L × B

⇒ Area of rectangle = l × 3

⇒ 81 = l × 3

⇒ l = 81/3

⇒ Length = 27 cm

Now, Perimeter of rectangle

Perimeter of rectangle = 2(L + B)

⇒ Perimeter of rectangle = 2(27 + 3)

⇒ Perimeter of rectangle = 2 × 30

⇒ Perimeter of rectangle = 60 cm

Hence, Perimeter of rectangle is 60cm