PERIMETERS A1

Area of a rectangle is 63 cm². Find its perimeter if its width is 7cm.

Solution

First we find length

A = l x w

63 = l x 7

63 = 7l

7       7

9 = l

Now length is 9cm.

We can find perimeter since we have both length and width.

P = 2(l + w)

=2(9 + 7)

=2 x 16

=32

Hence perimeter is 32cm

TRY THIS……………………..

Area of a rectangle is 84 cm². Find its perimeter if its width is 7cm.