In This Unit of Study…

Students will understand that a figure’s perimeter is found by measuring the length of each side and adding the lengths together.  They will explore perimeter as an attribute of a rectangle by using real-world objects to count unit segments.  Students will also be tasked with finding the perimeter of rectangles, triangles, squares, and pentagons when all side lengths are given.  It is not expected that students will use a formula to find the perimeter or to find the perimeter where there are unknown side lengths.

B.E.S.T. Benchmarks:

• MA.2.GR.2.1 Explore perimeter as an attribute of a figure by placing unit segments along the boundary without gaps or overlaps. Find perimeters of rectangles by counting unit segments.
• MA.2.GR.2.2 Find the perimeter of a polygon with whole-number side lengths. Polygons are limited to triangles, rectangles, squares, and pentagons.

Key Concepts:

• I can explore perimeter as an attribute of a figure by placing unit segments along the boundary without gaps or overlaps.
• I can find perimeters of rectangles by counting unit segments.
• I can find the perimeter of real-world objects, such as picture frames or desktops.
• I can find the perimeter of triangles, rectangles, squares, and pentagons with whole-number side lengths.
• I can use the associative and commutative properties of addition to find perimeter.
• I can represent perimeter with a number and appropriate units.