Question 620398
Since the length is to be twice the width, you can say l = 2w (length equals two times width).  That means that l is the same as 2w...so in your formula, instead of l, you can say 2w:  P = 2(2w + w)

Since perimeter is 50 ft, plug that in for P and solve:

50=2(2w+w)
50=2(3w)
50=6w
8.333...=w

w is 8.333... and l is twice that, or 16.666...

Since this is in terms of feet, we can write 8.333... ft as 8 ft, 4 inches (because .333... is 1/3, and 1/3 of a foot is 4 inches) and 16.666... ft as 16 ft, 8 inches.