Question 624443
First off, a perfect square is a perfect square. If you want to know why it is a trinomial (as opposed to a polynomial with four terms or two terms) here's why.


Let a and b be two arbitrary monomials (e.g. a = 5xy, b = 2z, etc.). Then


*[tex \LARGE (a+b)^2 = a^2 + ab + ba + b^2 = a^2 + 2ab + b^2]


Regardless of our choice of a and b (as long as they're monomials), *[tex \LARGE (a+b)^2] will have three terms. The exception is if a = 0, or a = b, etc. but in this case we'll assume the binomial is in simplest form.