## LESSON: Circumference of Circles

### Objectives/Vocab

## Objectives

- Identify ratio of circumference to diameter as pi.
- Find the circumference of circles given diameter or radius.
- Find diameter or radius of circles given circumference.
- Solve real world problems involving circumference of circles.

## Vocabulary

- Circumference
- the measure of the distance around the outside edge of a circle.

- Diameter
- the measure of the distance across the center of a circle.

- Radius
- the measure of the distance half-way across the circle. It is the measure from the center to the outer edge. The radius is also half the length of the diameter.

- Pi
- the ratio of the diameter to the circumference, 3.14

- Archimedes
- a Greek mathematician and philosopher who identified 3.14 as pi.