1. Circles Circumference and Area 6 th Grade Math LaVergne Middle School

2. Circles (terminology) Radius- The distance from the center of a circle to the edge.

3. Diameter- The distance across a circle, through the center. Circles (terminology)

4. Radius vs. Diameter The radius is ½ the diameter. The diameter is 2r.

5. Pi Pi is a Greek letter which is written as π. Pi written as a decimal value is 3.14 or as an improper fraction is 22/7. Pi is an approximation.

6. Circumference The circumference of a circle is the distance around a circle. Formula: C = πd C = 2πr 4 in.

7. Area of a Circle The area of a circle is the number of square units needed to cover the inside of a circle. (Think of a blanket) Formula: A = πr 2 7 cm.

8. Find the circumference and area. D = 24 cm

9. R = 0.75 in Find the circumference and area.

10. D = 78 cm Find the circumference and area.

11. The radius is shown in the circle below. Find the area and circumference. R = 52 cm

12. Find the circumference and area. D = 4.5 cm

13. Ticket Out! Which measurement is closest to the circumference of a circle with a radius of 3 cm? A.9.42 cm B.18.84 cm C.28.26 cm D.138.16 cm