Teacher presentation materials. Unit: 6.1 Area and Surface Area (Grade 6). 6.1 Area and Surface Area In this unit, students learn to find areas of polygons by decomposing, rearranging, and composing shapes. They learn to understand and use the terms “base” and “height,” and find areas of parallelograms and triangles. Students approximate areas of non-polygonal regions by polygonal regions. They represent polyhedra with nets and find their surface areas. Read More Lessons Resources Assessments Lessons Reasoning to Find Area 1 Tiling the Plane 2 Finding Area by Decomposing and Rearranging 3 Reasoning to Find Area Parallelograms 4 Parallelograms 5 Bases and Heights of P