Description: In Lessons 10 and 11, students decompose a quadrilateral. They rearrange the parts to form a new shape. They then use the new shape to tile, tracing its perimeter until a new larger shape (the complete tessellation) is formed. In Lesson 12, students measure side lengths and calculate perimeters. The next complexity is that students are given pictorial models, including the side lengths of polygons, from which they determine the perimeter in Lesson 13. Lesson 14 provides more complex problem solving; students determine the perimeter of a figure when whole number side length measurements are missing. In Lesson 15, students apply their basic understanding of perimeter to real world contexts. They explore how perimeter is used in everyday life, and they develop strategies for calculating perimeters using known information. Lesson 16 extends students' knowledge of perimeter to circles. Lesson 17 involves using all four operations to determine a perimeter and any missing measurements. Students develop strategies for finding part of a larger shape, for example, the blue rectangle in the figure below.*Teacher Advisor is 100% free.