This is a particular case, but it is not necessarily true. If triangles STU and XYZ are similar, the corresponding sides are in the same proportion. So, there exists a number
such that
![ST = kXY,\quad TU=kYZ,\quad SU=kXZ](https://img.qammunity.org/2019/formulas/mathematics/high-school/e89qtus6r9pi0ydvtap6cbcmk0t2tdwoz0.png)
So, if
, the corresponding sides are actually congruent, but it can be any other number. For example, if
, triangle XYZ is exactly twice as large as triangle STU, but they are still similar.