The length of a rectangle is 20m more than its width. If the perimeter

1.	The length of a rectangle is 20m more than its width. If the perimeter of the rectangle is 100m, then find the length and breadth of rectangle.
Answer» Let the width of a rectangle (b) = x m Then the length of a rectangle (l) = 20 more than its width = (x + 20) m Perimeter of the rectangle = 100 m ⇒ 2(1 + b) = 100 ⇒ 2(x + 20 + x) = 100 ⇒ 2(2x + 20) = 100 ⇒ 4x + 40 = 100 ⇒ 4x + 40 – 40 = 100 – 40 (Subtract 40 on both sides) ⇒ 4x = 60 4x 60 ⇒ 4x/4 = 60/2 (Divide by 4 on both sides) ⇒ x = 15 m ∴ Width x = 15 m Length = x + 20 = 15 + 20 = 35 m

The length of a rectangle is 20m more than its width. If the perimeter of the rectangle is 100m, then find the length and breadth of rectangle.

Answer»

Let the width of a rectangle (b) = x m

Then the length of a rectangle (l)

= 20 more than its width

= (x + 20) m

Perimeter of the rectangle = 100 m

⇒ 2(1 + b) = 100

⇒ 2(x + 20 + x) = 100

⇒ 2(2x + 20) = 100

⇒ 4x + 40 = 100

⇒ 4x + 40 – 40 = 100 – 40 (Subtract 40 on both sides)

⇒ 4x = 60 4x 60

⇒ 4x/4 = 60/2 (Divide by 4 on both sides)

⇒ x = 15 m

∴ Width x = 15 m

Length = x + 20 = 15 + 20 = 35 m