Polygon ABCD is dilated about the origin, O, to create polygon A′B′C′D′. Point A is located at (1, 3), and point A′ is located at (4, 12). Which type of dilation was used to create polygon A′B′C′D′, and what is the scale factor?
I don’t know what your textbook considers to be the different types of dilation, but this looks like uniform scaling with a scale factor of 4. The fact that the scaling is uniform means that it is stretched by the same scale factor in both the x- and y-directions. We see that the scale factor is 4 because