Question 909365: how to find the perimeter if the ratio is length 5 & width 3 and the area is 240 square
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! if the ratio of length to width is 5/3, then you get the following:
L/W = 5/3, where L stands for length and W stands for width.
solve for L to get L = 5W/3
The area of the rectangle is equal to 240.
formula for area is L*W = A
formula becomes L*W = 240
replace L with 5W/3 to get:
5W/3*W = 240
simplify to get 5W^2/3 = 240
multiply both sides of equation by 3 to get:
5W^2 = 240*3
divide both sides of equation by 5 to get:
W^2 = 240*3/5
simplify to get W^2 = 144
take the square root of both sides of equation to get W = 12
In equation of L = 5W/3, replace W with 12 to get:
L = 5*12/3
solve for L to get L = 20
you have L = 20 and W = 12
10*12 = 240 so the numbers are good because you know the area is 240.
you want to find the perimeter.
perimeter = 2L + 2W which becomes 2*20 + 2*12 which becomes 40 + 24 which becomes 64.
That's your solution.
Perimeter = 64 units.
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