Answer
The width of the field is $50$ yards and the length is $100$ yards.
Work Step by Step
Let us assume the width of the field is $ x $. Then, the length would be $ x+50$.
And equate the perimeter of the field as:
$\begin{align}
& 2\left[ x+\left( x+50 \right) \right]=300 \\
& 2\left[ 2x+50 \right]=300 \\
& 2x+50=150 \\
& 2x=150-50
\end{align}$
Then, simplify it further:
$\begin{align}
& x=\frac{100}{2} \\
& x=50
\end{align}$
Therefore, the width of the field is $50$ and the length is $50+50=100$.
Thus, the width of the field is $50$ and the length is $100$.
