Lesson objective: Compute the area of a circle when given the radius or diameter of a circle.

This lesson helps to build procedural skill with the formulas for the area of a circle. Real world examples are used here because it supports the relationship between the area and radius of a circle. This work develops students' understanding that circles have area like any other two dimensional shape.

Students engage in Mathematical Practice #8 (Look for and express regularity in repeated reasoning) as they use real world situations to explore the connection between the radius of a circle and its area.

**Key vocabulary:**

- area
- diameter
- radius
- pi (π)

**Special materials needed:**

- none