Question

Find the perimeter of the following rectangles:
a) Length = 5cm, Breadth = 3cm
b) Length and Breadth are in the ratio 4:3 and area is 1200 sq. meters.

Answer 1

a)

P = 2(l+b)

P = 2(8)

P = 16 cm

b) let length be 4x & breadth be 3x

ATQ.

A = 12x²

1200 = 12x²

x = 10 m

so , l = 40m

b = 30 m

so , P = 2× 70 = 140m

Answer 2

a). Perimeter of a rectangle-= 2(l+b).
=2(5+3)
=16 cm.
b). Perimeter of a rectangle=2(l+b)
Area =1200
l*b=1200
But, l/b=4/3.
4x*3x=1200.
Therefore, l=40 m.
b=30 m.

Perimeter=2(40+30)
=2(70)
=140 m.
Hope this will help you.