Scale Factor

Example:

Here, $\frac{XY}{UV}=\frac{12}{3}=4$ . So, the scale factor is $4$ .

Note that when a two-dimensional figure is enlarged ( dilated ) by a scale factor of $k$ , the area of the figure is changed by a factor of $k^2$ . In case of three-dimensional figures, when a figure is dilated by a scale factor of $k$ , the volume is changed by a factor of $k^3$ .