Arc Lengths and

1
Section 11-6

• Arc Lengths and
• Areas of Sectors

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Arc Length

• Part of the Circumference of a circle.

3

• To find the length of an arc
• Find the Circumference of the Circle
• Find the ratio of the measure of the arc to the
  whole circle.
• Find the product of the ratio and Circumference.

4
Example Find the length of arc AB.
5
In General
6
Sector of a circle

• A region bounded by two radii and an arc of the
  circle.

Sector AOB
The unshaded region is also a sector!
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Slices of Pizza are Sectors!
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• To find the area of a sector
• Find the Area of the Circle
• Find the ratio of the measure of the arc to
  the whole circle.
• Find the product of the ratio and Area.

9
Example Find the area of sector AOB.
10
In General