Answer: The width of the lawn is equal to 18 meters
Step-by-step explanation: If we have a rectangular figure, and the perimeter has been given, what that means is that we already have the addition of all four sides, which is equal to the perimeter, 126 meters in this instance.
However, we are also given the ratio of the two sides as being 5:2
That is, the ratio of the length to the width.
If the ratio is 5:2, then to calculate the length would be 5/7 ( that is, 5/{5+2} ). Similarly to calculate the width would also be expressed as 2/7 ( that is, 2/{5+2} ).
With that in mind, the length can be calculated as
{5/7} × 126
= 90
Remembering that the perimeter is calculated as
Per = 2L + 2W
Then it follows that 90 = 2L
Then L = 90/2
L = 45
Same goes for the width
{2/7} × 126
= 36
Note also that
36 = 2W
Then W= 36/2
W = 18