Properties of Equality & Congruence

a = a (or BD = BD)

Reflexive Property

If a = b, then b = a

Symmetric Property

If a = b and b = c, then a = c

Transitive Property

If a = 5, then x + a becomes x + 5

Substitution Property

If a = b, then a + c = b + c

Addition Property of Equality

If a = b, then a - c = b - c

Subtraction Property of Equality

If a = b, then a * c = b * c

Multiplication Property of Equality

If a = b, then a/c = b/c

Division Property of Equality

a(b + c) = ab + ac

Distributive Property