Answer
length of the rectangular soccer field is $ 100 \; yard $
and width of the rectangular soccer field is $ 50 \; yard $
its dimensions are $ 50 \; yd \; by \; 100 \; yd $
Work Step by Step
Let $ l $ represents the length.
and $ w $ represents the width.
The rectangular soccer field is twice as long as it is wide.
In mathematical form.
$ l=2w $ ...... (1)
the perimeter of the soccer field is $ P=2l+2w $.
From the question $ P=300 \; yards $ plug into above equation.
$ 300=2l+2w $
Substitute the value of $ l $ from equation (1).
$ 300 = 2(2w)+2w $
$ 300 = 4w+2w $
$ 300 = 6w $
$ \frac{300}{6} = w $.
$ 50 = w $
Subsitute above value into equation (1).
$ l=2(50) $
$ l=100 $.