Instructional Activity# A Tale of Two Triangles (Part 2)

Lesson 7. Unit 1. Grade 6 Open Up Resources

Open Up Resources15 min(s)

This Instructional Activity is a part of the Lesson 7, Unit 1, Grade 6. Previously, students decomposed quadrilaterals into two identical triangles. The work warmed them to the idea of a triangle as a half of a familiar quadrilateral. This activity prompts them to think the other way-to compose quadrilaterals using two identical triangles. It helps students see that two identical triangles of any kind can always be joined to produce a parallelogram. Both explorations prepare students to make connections between the area of a triangle and that of a parallelogram in the next lesson.