10.7 Areas of Circles and Sectors 2011 1 March 08, 2011 Feb 242:16 PM Warmup 1. FInd the circumference 2. Find the measure of Abc 3. Find the length of xy ( ( 4.5 a b c 101 o 7 112 o
10.7 Areas of Circles and Sectors 2011
1
March 08, 2011
Feb 242:16 PM
Warmup1. FInd the circumference 2. Find the measure of Abc 3. Find the length of xy
( (
4.5
a
b
c101o7
112o
10.7 Areas of Circles and Sectors 2011
2
March 08, 2011
Apr 218:04 AM
Challenge Problem
10 ft
8 ft
10.7 Areas of Circles and Sectors 2011
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March 08, 2011
Apr 2012:26 PM
107: Areas of Circles, Sectors, and Segments.
Objective: Find the area of circles, sectors, and segments.
10.7 Areas of Circles and Sectors 2011
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March 08, 2011
Apr 202:29 PM
RefresherHow do you find the circumference of a circle?
How do you find the area of a circle?
10.7 Areas of Circles and Sectors 2011
5
March 08, 2011
Apr 202:32 PM
New Vocabulary: SECTOR
A sector is a region bounded by two radii of a circle.
O
X
Y
The blue shaded region is called sector XOY.
How can we find the area of a sector if we know the measure of XOY ?
10.7 Areas of Circles and Sectors 2011
6
March 08, 2011
Apr 217:32 AM
10.7 Areas of Circles and Sectors 2011
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March 08, 2011
Apr 217:37 AM
Find the area of sector ZOM.
A circle has a diameter of 20 cm. What is the area of a sector bounded by a 208o major arc?
10.7 Areas of Circles and Sectors 2011
8
March 08, 2011
Apr 217:45 AM
Segment of a circle.
New Vocabulary: SEGMENT
A part of a circle bounded by an arc and the segment joining its endpoints is a segment of a circle.
10.7 Areas of Circles and Sectors 2011
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March 08, 2011
Apr 217:51 AM
O
A
B
How do we find the area of segment AB given the measure of AOB and the radius ?
10.7 Areas of Circles and Sectors 2011
10
March 08, 2011
Apr 217:56 AM
Area of a segment
10.7 Areas of Circles and Sectors 2011
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March 08, 2011
Apr 217:59 AM
Find the area of segment AB.
10.7 Areas of Circles and Sectors 2011
12
March 08, 2011
Apr 218:01 AM
A circle has a radius of 12 cm. Find the area of the smaller segment of the circle bounded by a 60o arc.
Practice
10.7 Areas of Circles and Sectors 2011
13
March 08, 2011
Apr 218:15 AM
Homework
pg 577 # 1, 3, 719 even, 23, 26, 30
10.7 Areas of Circles and Sectors 2011
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March 08, 2011
Mar 82:40 PM