The Circumference of a Circle How many times does the diameter fit around the circumference? Choose your number. 1 1½ 2 2½ 3 3½ 4 d 1 2 Diameter(d) Circumference (C) In terms of the radius C = 2πr 3
It’s the same for all circles!
The Area of a Circle 4 Sectors
8 Sectors
16 Sectors
32 Sectors
As the number of sectors , the transformed shape becomes more and more like a rectangle. What are the dimensions of this rectangle? What is its area in terms of the radius? Remember C = 2πr A = πr x r = πr2