Calculating Area and Circumference of Circles
9th Grade · Math · 45 min
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Learning Objective
I can calculate the area and circumference of circles given the radius or diameter.
- 1
The diameter is the distance across the center of the circle, while the radius is the distance from the center to the outer edge; the radius is half the diameter.
- 2
The circumference of a circle is the distance around the circle, and can be calculated using the formula C = πd or C = 2πr, where π is approximately 3.14.
- 3
The area of a circle is calculated using the formula A = πr², where r is the radius and π is approximately 3.14.
