Question

what is the scale factor of UVW to XYZ?

Answer 1

XZ ~ UW
UV ~ XY
VW ~ YZ

Take any corresponding side and the ratio of it is your answer. 

Example : 

XZ / UW = 14/ 2 = 7
XY / UV = 21 / 3 = 7
YZ / VW = 28 / 4 = 7 

Therefore, your answer is B. 7

Answer 2

Answer:

The scale factor is 7.

Step-by-step explanation:

In the image attached, you can observe that both triangles are similar, and we can establish the following proportionality

$\frac{UW}{XZ}=\frac{UV}{XY}=\frac{WV}{ZY}$

Replacing the length of each side, we have

$\frac{2}{14}=\frac{3}{21}=\frac{4}{28}\\\frac{1}{7}= \frac{1}{7}=\frac{1}{7}\\7=7=7$

Therefore, the scale factor between these triangles is 7, that is, ΔXYZ is seven times bigger than ΔUVW