The length of the rectangle is 28 inches.
To solve this problem, we can use the formula for the perimeter of a rectangle: P = 2(l + w), where l is the length and w is the width.
Substituting the given values, we get: 56 = 2(l + 4w).
Solving for l, we get: l = 28.
Therefore, the length of the rectangle is 28 inches.