Answer:
1 unit shorter
Explanation:
By plotting the given points in the coordinate plane,
We get a rectangle ABCD having vertices,
A(-1,6), B (3,6), C (3,1), D (-1,1)
By the distance formula,
Shorter side or width of the rectangle,

Longer side or length of the rectangle,

The difference between length and width,

Hence, the width of rectangle is 1 unit less than the length.