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 Description  
 Dilation:  A transformation that changes the size of an object, but not the shape.


The original image is the polygon labeled CDEFG. The image after dilation is the polygon labeled C'D'E'F'G'. The scale factor can be determined by the ratio:

r = length C'D'/length CD.

If this r < 1 then the image is smaller than the original polygon.
If this r > 1 then the image is larger than the original polygon.
If this r = 1 then the image is the same as the original polygon.

A JavaSketchPad page is provided for you to explore dilations. Move any red point and observe what happens. Try various positions for point P (i.e., inside and outside the figure).