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

This lesson helps to build procedural skill with exploring the realtionship between area, radius and diameter. Real world problems are used here because they support the investigation of the circle relationships. This work develops students' understanding that circles have area like any other shape.

Students engage in Mathematical Practice #8 (look for and express regularity in repeated reasoning) as they struggle with finding the radius and diameter of a circle when given the area (mastering the algebraic relationship between radius and area).

**Key vocabulary:**

- area
- circle
- diameter
- pi (π)
- radius

**Special materials needed:**

none