This document provides instruction on perfect square trinomials including defining them, identifying them, factoring them, and working practice problems. It begins by defining a perfect square trinomial as the result of squaring a binomial with the first and last terms being perfect squares and the middle term being twice the product of the square roots of the first and last terms. Examples are provided to illustrate. The document then provides guidance, activities, and an assessment to practice identifying, factoring, and working with perfect square trinomials.