Learning goals: Teacher Facing Apply understanding of circumference to calculate the perimeter of a shape that includes circular parts, and explain (orally and in writing) the solution method. Compare and contrast (orally) values for the same measurements that were calculated using different approximations for $\pi$. Explain (orally) how to calculate the radius, diameter, or circumference of a circle, given one of these three measurements. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 7.3 Measuring Circles, Grade 7.