Two figures are congruent if they have the same shape and size.

Two angles are congruent if they have the same measure.

Two figures are similar if they have the same shape but not necessarily the same size.

All of the figures below are congruent since they all have the same shape and size.

The figures below are NOT congruent. Although they are the same shape, they are different sizes. Figures that are the same shape but different in size are similar.

The two figures below are NOT congruent since they do not have the same shape.