# Exploring Measures of Circles

7th grade

**Description**

Explore relationships between the parts of a circle in order to discover the formulas for finding the circumference and area of circles.

### Hook

If you're going on a ten mile bike ride, which bike would you choose? Why?

### Lessons

Lesson 1 of 2

Measure circular objects to explore the relationship between **circumference** and **diameter** of a** circle** in order to discover the** ratio**, **Pi.**

Lesson 2 of 2

Discover the **area **formula of **circles** by separating into congruent shapes and using their understanding of other polygons.

### ARC Assessement

Have students revisit the Hook in the beginning of the ARC and ask students to reassess their answer. "Now that you have learned about the parts of a circle, and circumference and area of circles, would you change your answer? Why or why not? What is your mathematical justification for the bike you have chosen?"

### Technology Resources