Answer:
The width is 10 feet.
Step-by-step explanation:
We know that the area of a rectangle is given by the formula:
[tex]\displaystyle A=L\cdot W[/tex]
Where L is the length and W is the width.
We are given that the length of the rectangle is three times the width. In other words:
[tex]L=3W[/tex]
The total area is 300 square feet. And we want to determine the width of the rectangle.
So, substitute 300 for A and 3W for L:
[tex](300)=(3W)\cdot W[/tex]
Multiply:
[tex]300=3W^2[/tex]
Divide both sides by three:
[tex]W^2=100[/tex]
And take the principal square root of both sides. So:
[tex]W=10[/tex]
Thus, the width of the rectangle is 10 feet.