Determining Congruence

Congruence transformation is another name for rigid motion or combination of rigid motions. Let's recall its definition. $$\begin{array}{c}\text{A rigid motion is a transformation}\\ \text{that preserves the length and angle}\\ \text{measures of the preimage.}\end{array}$$ In other words, the above means that a rigid motion maintains the exact size and shape of a figure. Therefore, a congruence transformation does not change the size of a figure. This means that there is no such congruence transformation.