In this lesson, students revisit the distributive property as they multiply binomials. Then, students focus on recognizing a perfect square trinomial and rewriting these trinomials as a squared binomial using the distributive property. As students recognize patterns in these perfect square trinomials and squared binomials, students build on the work from earlier courses as they look for regularity in repeated reasoning (MP8).

Then, students rewrite perfect square trinomials in an equation that describes a circle in order to find a the center of a circle. In this lesson, the equations involve only perfect square trinomials in order to highlight that rewriting the equation in an equivalent form makes it easier to identify the center and radius of the circle. 

In upcoming lessons, students will build on these algebraic skills by completing the square to identify a circle’s radius and center, so it is not necessary to introduce that idea in this lesson.