The fence means perimeter around the court. So a tennis court's perimeter is 600 feet fence. The perimeter of a rectangle is 2 times the sum of the rectangle's length and the rectangle's width.
It is given that length equals 60 more than width i.e. l = w + 60, where l is the length of the court and w is the width of the court.
The perimeter of a court = 600 = 2 (l + w) = 2l + 2w = 2 (w +60) + 2w, this becomes, 2w + 120 + 2w = 600; 4w = 480, w = 120.
Since l = w + 60, l = 120 + 60 = 180. So length of a court is 180 feet and the width of a court is 120 feet.
