How can you explain the relationship between congruence and similarity in both 2- and 3-dimensional figures?

Question

How can you explain the relationship between congruence and similarity in both 2- and 3-dimensional figures?

Answer 1

Similar figures have the same shape but possibly different sizes. E.g., all cubes have the same shape but perhaps different edge lengths.

 

Congruent figures have both the same shape (are similar) and the same size. E.g., a set of children's blocks are (close to being) all congruent cubes.