Question

3. Use an algebraic equation to solve the problem,A rectangle is 3 times as long as it is wide. The perimeter is 60 cm. Find the dimensions of the rectangle.Round to the nearest tenth if necessary.7.5 cm by 22.5 cm7.5 cm by 52.5 cm20 cm by 60 cm15 cm by 22.5 cm​

Answer 1

7.5 cm by 22.5 cm

Explanation:

let the width be w , then length is 3w (3 times the width )

the perimeter (P) of a rectangle is calculated as

P = 2( length + width )

given P = 60 cm

substitute P = 60 , then

60 = 2( 3w + w)

60 = 2(4w)

60 = 8w ( divide both sides by 8 )

`(60)/(8)` =
`(8)/(8)` w , that is

7.5 = w

and length = 3w = 3 × 7.5 = 22.5

dimensions of rectangle are 7.5 cm by 22.5 cm