Length = 502 ft
Width = 212 ft
Explanation:
Recall the formula for the perimeter of a rectangle of length "L" and width "W":
Perimeter = 2 L + 2 W = 1428 ft
Now, since the length is 78 ft more than twice the width, then we can write this in mathematical form as:
L = 2 W +78
so, 2 W = L -7 8
and now replace "2 W" with it equivalent "L - 78" in the first perimeter equation and solve for "L":
2 L + L - 78 = 1428
3 L = 1428 + 78
3 L = 1506
L = 1506/3
L = 502 ft
Then the width W can be obtained via:
2 W = L - 78
2 w = 502 -78
2 W = 424
w = 212 ft