WARM UP

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WARM UP

1. Find the circumference and area of a circle with
   diameter 7y.
2. What is the area of an equilateral triangle with
   an apothem of 18?
3. A basketball rim has a diameter of 18 inches.
   Find the circumference of the rim and the area it
   encloses. Round the nearest whole number.

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Section 11.6

• Arc Lengths and Areas of Sectors

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AREA of CIRCLE

• Find the area of the whole circle.

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Arc Length

• Find the arc length.

How much of the circumference do I need?
¼
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Find the Arc Length
60o
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Area of a portion of a circle

• Find the area of the shaded portion of the
  circle.

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Area of a Sector
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Try this one!
A
Hint Find the area of the whole sector and
subtract the area of the triangle.
60o
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B
9
6
3
60o
6
10

• A circle has area 160p cm2. If a sector of the
  circle has area 32p cm2,
• Find the measure of the arc of the sector.
• Find the length of the arc.

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SAT Question

• 1) In the figure the radius of the circle O is
  3. What is the perimeter of the shaded region?

HINT Find the length of the side of the
triangle in the region and the arc length of the
region.
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Practice Problems

• Page 453
• Classroom Exercises
• 1 4, 6

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Its Movie Time!

• Circumference Video