The (a + b)² formula is used to find the square of a binomial. This formula is also used to factorize some special types of trinomials and is one of the algebraic identities. The (a + b) whole square formula is the result of the square of the sum of two terms a and b.

The (a + b)² formula is widely used to factorize the trinomials of the form a² + 2ab + b². This formula is explained below along with solved examples in the following section.