Answer:
line B'C' = 1
m<C'D'A' = 90 degrees (it is still a rectangle)
Step-by-step explanation:
Dilation of coordinates:
Original: d:(3,2), a:(3,4), b:(7,4), c:(7,2)
Divide all numbers by 2.
Altered: d:(1.5,1), a:(1.5,2), b:(3.5,2), c:(3.5,1)