A dilation is a type of that changes the size of a figure without changing its shape. Dilations can make a figure larger or smaller. For example, the first dilation below makes the triangle larger. The second dilation makes the triangle smaller.
In a dilation, the original figure is called the preimage.
The dilated figure is called the image.
Figures are dilated from a fixed point, called the center of dilation.
When you dilate a figure, the scale factor determines how much smaller or larger the image will be.
If the scale factor is between 0 and 1, the image is smaller than the preimage. Dilations with a scale factor between 0 and 1 are called reductions.
If the scale factor is greater than 1, the image is larger than the preimage. Dilations with a scale factor greater than 1 are called enlargements.
When a figure is dilated, you can name each new point using the prime symbol, '. For example, the dilated image of point Q
would be point read prime." 
