Question

5. What will happen to the perimeter of a rectangle if its length is doubled and breadth remains the same? ​

Answer 1

Answer:

Let the rectangle be 10 cm x 5 cm. Its perimeter = 2(10+5) = 30 cm.

If the length is doubled while the breadth remains the same, the perimeter = 2(20+5) = 50 cm.

So the perimeter increases by (50–30)*100/30 = 20*100/30 = 66.67%.

Let another rectangle be 40 cm x 20 cm. Its perimeter = 2(40+20) = 120 cm.

Here on doubling the length of the rectangle, the perimeter = 2(80+20) = 200 cm.

Here the perimeter increases by (200–120)*100/120 = 80*100/120 = 66.67%.