Answer:
18,12
Step-by-step explanation:
W (1, -2), X (7,-2), Y (7,-6), and Z (1, -6).
To dilate the shape, multiply it's coordinates by the scale factor.
W'(3,-6), X'(21,-6), Y'(21,-18), Z(3, -18)
The distance formula: 
plug W'(3,-6) and X'(21,-6) in to get the length

plug X(21,-6) and Y(21,-18) to get the width

