This is a zip file containing lessons on circumference and area of circles, including the relationship between diameter and circumference (pi). The lessons include the standard, essential question, spiral warm up, diagrams and interactives, model problems, practice problems, and a closing. The answers pop in as you work through the power point lessons. This allows you to use this as a teaching tool for the whole class, small group, or individual. A culminating quiz is included as well.