Question

Perimeter of a square and a rectangle is same. If a side of the square is 15 cm and one side of the rectangle is 18 cm, find the area of the rectangle.

Answer 1

Let breadth of rectangle = b cm

Given, length of rectangle = 18 cm

And side of a square = 15 cm

∴ Perimeter of a square = 4 × Side = 4 × 15 = 60 cm

Given, Perimeter of rectangle = Perimeter of square

⇒ 2 × (Length + Breadth) = 60

⇒ 2(18 + b) = 60

⇒ `(2 xx (18 + b))/2 = 60/2`  ...[Dividing both sides by 2]

⇒ 18 + b = 30

⇒ b = 30 – 18   ...[Transposing 18 to RHS]

⇒ b = 12

Now, Area of rectangle = Length × Breadth

= 18 × 12

= 216 sq cm