The symbol ‘∼’ is used to denote similarity, but similarly does not mean the same in size. When all comparable angles are identical, and all lengths are enlarged (or shrunk) by the same ratio, known as the magnification ratio, two figures are said to be similar. A transformation that takes figures to similar figures is called a similarity.

The symbol for similarity is ∼ (similar to the symbol for congruence, which was ≅).

The symbol to express similar figures is the same symbol for congruence i.e. "∼" but similar does not mean the same in size.

The equivalent sign indicates that two numbers, concepts or ideas are similar under a particular condition. While the equal sign represents the fact that two factors are the same under all conditions, equivalence refers to portions of equality between the two or more factors.