What is meant by Dilation?
Introduction to dilations
Dilation also known as enlargement is the only form of transformation that does not preserve the congruency of the figure and thus is a nonrigid transformation.
Dilation is the process in which the shape of the object remains the same while the size of the object changes
The requirement for dilation is the center with respect to which an object has to be dilated and the scale factor that determines the relative distance of the object from the center with that of image from the center. In the same way as rotation, all objects and their respective images can be joined with a line all passing through the center. The ratio of corresponding sides (for example a polygon) maintains a constant value for any dilated figure for all points. The given figure is an example of dilation in which the object has been dilated with scale factor 3 from the center shown. Scale factor means that the ratio of distance of image from the center is 3 times the distance from object to center.
i.e. OA'/OA=3
The same ratio is maintained by all of the points of the image and object.
If the ratio is higher than 1, then the given object has been magnified in the image, if it is less than 1, the object gets diminished in the image and if the scale factor is 1 then the object and image are of same size.
