Question

A rectangular skate park is 60 yards long and 50 yards wide

Answer 1

It is unclear what you want to do, but in the case where they give you the length and the width, it is most likely they are asking for either area or perimeter. For Area, it is length times width.
A = l x w
A = 60 yards x 50 yards
A = 3000 square yards.
For Perimeter of the rectangle, it is 2 of the lengths plus 2 of the widths.
P = 2 ( 60 yards ) + 2 ( 50 yards )
P = 120 yards + 100 yards
P = 220 yards
I hope this helps :-)