Answer:
CD = 18 units
Step-by-step explanation:
Given a rectangle with length x and width y, the perimeter is:
P = 2x + 2y
Here, we note that x = AB = CD, y = AD = BC, and P = 64 units. So:
2AB + 2BC = 64
We know that AB = 3z and BC = 2z + 2; plug these in:
2 * (3z) + 2 * (2z + 2) = 64
6z + 4z + 4 = 64
10z = 60
z = 6
Now that we've solved for z, we can find AB and, hence, CD because AB = CD.
AB = 3z = 3 * 6 = 18 units
Thus, CD = 18 units, as well.
