Unit 2, Lesson 8# Similar Triangles

Open Up Resources 50 min(s)

In this lesson, students understand that for the special case of triangles, having two corresponding angles of equal measure is sufficient for establishing similarity. Students know how to decide if two triangles are similar just by looking at their angle measures. In the previous lesson, students found that, in order to check if two quadrilaterals are similar, it is important, in general, to check geometry toolkits that corresponding angles are congruent and that corresponding side lengths are proportional. Students will use the similarity criterion in future lessons to understand the concept of the slope of a line.