Answer: 170 meters.
Step-by-step explanation:
1. The formula for calculate the perimeter of a rectangle is:
[tex]P=2l+2w[/tex]
Where [tex]l[/tex] is the lenght and [tex]w[/tex] is the width.
2. You must solve for the lenght.
3. The problem gives the perimeter and the width, then, when you substitute these values you obtain the following result:
[tex]2l=P-2w\\l=\frac{P-2w}{2}\\l=\frac{940m-2(300m)}{2}\\l=170m[/tex]
