Q5 of 18 Page 226

The length of a rectangle is three times its width. If the perimeter is 84 m, find the length of the rectangle.

Given: Length of rectangle = 3 × width of the rectangle


Let length and breadth of the rectangle be ‘l’ m and ‘b’ m respectively.


⇒ l = 3 × b = 3b


We have perimeter of rectangle = 84 m


We know, Perimeter of rectangle = 2 (length + breadth) ⇒ 84 = 2(l + b)


But, l = 3b


⇒ 84 = 2(3b + b)


⇒ 84 = 2(4b)


⇒ 8b = 84



So, length of rectangle l = 3b = 3 × 10.5m


∴ l = 31.5 m


Thus, length of the rectangle is 31.5 m.


More from this chapter

All 18 →
3

A tile is a square of side 20 cm. How many would such tiles be required to cover the floor of a square bathroom of side 3 m?

 4

A carpet is 30 m 75 cm long and 80 cm wide. Find its cost at Rs. 150 per square meter.

 6

Find the length of one side of a square whose perimeter is equal to that of a rectangle with length and breadth 100 meters and 62 meters respectively.

 7

The area of a square field is 8281 m2. Find the length of its side.