Recall that the scale factor is the ratio of the length of a side of the image to the length of the corresponding side of the preimage.
See solution.
Practice makes perfect
When we have two figures such that one is the image of the other under a certain transformation, we first find the scale factor by taking the ratio of the length of a side of the image to the length of the corresponding side of the preimage.
k = Side of the image/Corresponding side of the preimage
Once we know the scale factor, depending on its value we determine what type of transformation we are dealing with. We have three cases.
If 0< k < 1, then the sides of the preimage are longer than the sides of the image. This means that the transformation is a reduction.
If k = 1, then the sides of the preimage and the sides of the image have the same length. Therefore, the transformation is a congruence transformation.
If k > 1, then the sides of the preimage are shorter than the sides of the image. In consequence, the transformation is an enlargement.
