Question

The length of a rectangle is three more than twice its width the perimeter of a rectangle is 42 cm what is the length of the rectangle?

Answer 1

The length of the rectangle is 15 cm.

Explanation:

breadth(b)=?

length(l)= 3+2b

perimeter(P)= 42 cm

Now,

P = 2 ( l+b )

or, 42= 2 ( 3+2b+b)

or, 42 = 2 ( 3+3b)

or,
`(42)/(2)` = 3+3b

or, 21 = 3+3b

or, 21-3 =3b

or, 18 = 3b

or,
`(18)/(3)` = b

or, 6 = b

Here, Breadth(b)= 6 cm

Length (l) = 3 + 2*6

= 3 + 12

=15 cm