1. Circumference & Area of a Circle
MA.6.4.1: Estimate the circumference and area of a circle
Period 4

2. Definition
Circumference is the distance around a circle or the perimeter.
Formula = Pi x diameter
Area is the measure of the amount of surface enclosed by the boundary of a figure.
Formula = r x r x pi

3. Example: Circumference
Formula = Diameter x Pi Diameter = 2 in. Pi = x 3.14 = 6.28 in.
2 in.

4. Example: Area
Formula = radius x radius x Pi Radius = 5 cm. Pi = x 5 x 3.14 = 78.5 sq. cm.
5 cm.

5. Problem
Kristle wanted to find the area and the circumference of a circle with a diameter of 26 in. Find the area and circumference of her circle.
26 in.

6. Solution
The area of Kristle’s circle is in. because if the diameter is 26 in. then the radius must be 13 in. (26/2=13) x 13 = x 3.14 = sq. in.
The circumference of Kristle’s circle is in. because 26 x 3.14 = 81.64

7. Credits I give credit to my parents for giving me support……
I also give credit to my math teacher, Mr. Imamura for teaching me what the circumference and area is and the formula for each……
I also give credit to my friends (Kristle mostly) for helping me use
Microsoft PowerPoint:
Definition from Connected Mathematics.
Hope you enjoyed my fantabulous presentation on the circumference and the area of a circle.