A dilation is a transformation [tex]D_{o,k}(x,y)[/tex], with center O and a scale factor of k that is not zero, that maps O to itself and any other point P to P'.
The center O is a fixed point, P' is the image of P, points O, P and P' are on the same line.
In a dilation of [tex]D_{o, \frac{1}{2} }(x,y)[/tex], the scale factor, [tex] \frac{1}{2} [/tex] is mapping the original figure to the image in such a way that the
distances from O to the vertices of the image are half the distances
from O to the original figure. Also the size of the image is half the
size of the original figure.
Therefore, If [tex]D_{o, \frac{1}{2} }(x,y)[/tex] is a dilation of △ABC, the truth about the image △A'B'C' are:
AB is parallel to A'B'.
[tex]D_{o, \frac{1}{2} }(x,y)=( \frac{1}{2}x, \frac{1}{2}y) [/tex]
The distance from A' to the origin is half the distance from A to the origin.