Final answer:
Two figures are similar if they have congruent angles and proportional side lengths, which can be proven using transformations like scaling and rotation.
Step-by-step explanation:
These two figures are similar because the angle measures are congruent and the side lengths are proportional. To prove these figures are similar, you can perform a sequence of transformations. You would need to use the transformations of scaling (dilation) and rotation, and sometimes translation or reflection depending on their initial positions.