Dilation

Definition:  A dilation (size transformation) with a center C and a scale factor of k is the transformation that maps every point P in the plane to a point P' such that the following properties are satisfied:

  1. If k>0 then P' lies on the ray CP (the initial point being C) such that CP'=k(CP).

  2. If k<0 then P'-C-P such that P'C=|k|CP

Example:

P' lies on ray CP such that CP'=2(CP). Thus, P is the midpoint of the line segment CP.