Help on this question please

Acity plans to build a new rectangular-shaped park. the perimeter of the park will be 940 meters. the width of the park will be 300 meters. what will be the length, in meters, of the new park?

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

Which describes the difference between the graph of f(x)=x^2 and g(x)=-(x^2-2)