The perimeter of the rectangle below is 132 units. Find the length of side CD

The opposite sides of a rectangle will always be congruent. If they aren't, it's not a rectangle.
To find CD, you need to find what z is. This can be found using the given, the perimeter, and plugging that into the perimeter formula using the information given. You end up with 2(4z - 3) + 2(3z - 1) = 132. Solve for z and you find that z = 10.
CD is congruent to AB, which is 3z -1. Plug z in to get AB = 29. Since AB = CD, CD = 29.
The formula for the perimeter of a rectangle is
P = 2(L+W)
we are given the perimeter, and the length and width. we can plug everything we are given into the equation to solve for Z.
132 = 2[(4z-3) + (3z-1)]
132 = 2[ 7z-4]
132 = 14z-8
140=14z
10=z
now that we have the value of z, we can plug it in for the equation for line AB. line AB and line CD are the same since this is a rectangle
CD = 3z-1
CD = 3(10)-1
CD= 30-1
CD=29 units
hope this helped!