Question

The width of a rectangular Play ground is 18 m less than the length find the width when the perimeter of the rectangle is 84 m

Answer 1

Solution

Step 1

Write the formula for the perimeter of a rectangle'

$\begin{gathered} Perimeter\text{ of a rectangle = 2L + 2W} \\ L\text{ = length} \\ W\text{ = width} \end{gathered}$

Step 2

Let then length = m

Width = m - 18

perimeter = 84m

Step 3

$\begin{gathered} Perimeter\text{ = 2L + 2W} \\ 84\text{ = 2m + 2\lparen m - 18\rparen} \\ 84\text{ = 2m + 2m - 36} \\ 84\text{ + 36 = 4m} \\ 120\text{ = 4m} \\ \text{m = }\frac{120}{4} \\ \text{m = 30} \end{gathered}$

Final answer

Length = 30m

Width = 12m