Big Ideas: Perimeter is the measure of the distance around a two-dimensional shape. The length of the perimeter of a polygon is the sum of the lengths of the sides. You can use non-standard units to understand the concept of perimeter. This lesson builds on developing students' understanding of perimeter and shapes attributes. This task requires students to use manipulatives and make sense of the characteristics and relationships between shapes and perimeter. Students will describe, analyze, and explore perimeter of polygons. Students are presented with a situation in which they have to create a polygon and asked to use a Geoboard to find its perimeter by examining the lengths of its sides. This builds toward the ability to apply perimeter formulas for rectangles in real-world and mathematical problems. Vocabulary: perimeter, non-standard unit, distance, length, polygon Special Materials: Geoboard or dot paper Inch tiles (optional)