## public lessons

These demonstration lessons are taught by practicing teachers and professional developers. These lessons have been extensively field-tested in multiple settings and refined over time, and are generally presented to an audience of participating students and observing teachers.

## featured lesson

**Modeling through Geometry: Circumference of a Cup’s Roll**

Molly McNinch leads her high school Geometry students in a lesson to compare real-world rolling geometric “cup” shapes, analyze and identify which shapes will generate larger or smaller circles when rolled, and present an argument and justification to their peers. Students need to understand the ways in which the diameter, radius, slant length, and roll radius relate to each other.