1. Area and Circumference of Circles

2. 1. Radius- any line segment that connects the center to a point on the circle VOCABULARY Radius

3. 2. Diameter- any line segment that passes through the center of the circle and connects two points on the circle. The diameter is twice the length of the radius.

4. 3. Circumference is the word used to describe the distance around the outside of a circle.

5. A=π r 2 Formulas C= 2πr Or C= πd

6. What is pi? Pi is the ratio of the circumference of the circle to its diameter. π

7. Pi is an infinite decimal. Lets take a look….. The first 500 digits of pi.

8. Practice Problems 1. A hot tub has a diameter of 6 feet. What is the circumference and area of the hot tub?

9. Practice Problems 2. The circumference of your CD is 28.26 cm. What is the radius?

10. Practice Problems 3. The radius of a circular rug is 4 ft. What is the circumference and area of the rug?

11. http://www.ballandclaw.com/upi/ pi.50000.html