To get the square of a trinomial, you should:
· square the first , second and last term
· get the product of the first and second term and double it
· get the product of the first and last term and double it
· get the product of the last and second term and double it
Example:
(a + ab +b)²
= a² + a²b³ +b² + a²b + ab + ab²
