a rectangular security area is enclosed with 200 ft of fencing. if this rectangular area is arranged so that the ratio of the length to the width is 5/3, find the dimensions.

2 answers

In a rectangle, the parallel sides are equal. Thus,

x = width
5x/3 = lenght

2x + 2(5x/3) = 200
6x/3 + 10x/3 = 200
16x/3 = 200
x=37.5

Now, you have the short side. To find the long one, multiply by ratio:

37.5 * 5/3 = 62.5

Control:
2*37.5 + 2*62.5 = 200
200 = 200
5L = 3W

L = 3/5W

2L + 2W = 200

Substitute 3/5W for L in last equation and solve for W. Insert that value into the first equation and solve for L. Check by inserting both values into the last equation.