Learning goals: Teacher Facing Comprehend the word “pi” and the symbol $\pi$ to refer to the constant of proportionality between the diameter and circumference of a circle. Create and describe (in writing) graphs that show measurements of circles. Generalize that the relationship between diameter and circumference is proportional and that the constant of proportionality is a little more than 3. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 7.3 Measuring Circles, Grade 7.