Teacher presentation materials. Unit: 3.7 Two-dimensional Shapes and Perimeter (Grade 3). 3.7 Two-dimensional Shapes and Perimeter Unit Goals Students reason about shapes and their attributes, with a focus on quadrilaterals. They solve problems involving the perimeter and area of shapes. Section A Goals Reason about shapes and their attributes. Section B Goals Find the perimeter of two-dimensional shapes, including when all or some side lengths are given. Section C Goals Solve problems involving perimeter and area, in and out of context. Section D Goals Apply geometric understanding to solve problems. Read More Lessons Resources Assessments Practice Glossary Lessons Section A: Reas