, a dilation with center O
and nonzero scale factor k
maps any point P
to a point
P' determined as follows:
(1) If k > , P' lies on ray OP and OP' = k * OP.
(2) If k < 0, P' lies on the ray opposite ray OP and OP' = |k| * OP.
(3) The center O is it's own image.
If |k| > 1, the dilation is an expansion.
If |k| < 1, the dilation is a contraction.