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Geometry Section 8-3A Geometry Section 8-3A

Inscribed AnglesInscribed Angles

Page 584Page 584

Worksheet Answer Key1) D2) B3) E4) A5) C6) 201.067) .798) 28.279) 52.3610) 126.111) 603.1912) 37.713) 21.4614) 73.0615) 516) 1217) 3.91

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Vocabulary:Vocabulary:

Inscribed Angle: An angle with its vertex on a circle and sides that contain chords of a circle.

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Inscribed AnglesInscribed Angles

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We know that the measure of a central angle is equal to the measure of the arc it contains.

Inscribed Angle Theorem:The measure of an inscribed angle is half the measure

of its intercepted arc.

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Try It:Try It:

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Find the measure of each angle or arc indicated by a variable.

48o

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Try It:Try It:

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Find the measure of each angle or arc indicated by a variable.

80o

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Try It:Try It:

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Find the measure of each angle or arc indicated by a variable.

90o

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Theorems:Theorems:

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If two inscribed angles intercept the same arc, then they are congruent.

An inscribed angle that intercepts a semicircle is a right angle.

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Exercises:Exercises:Find the measure of each angle or arc.

#1

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136o

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Exercises:Exercises:Find the measure of each angle or arc.

#2

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46o

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Exercises:Exercises:Find the measure of each angle or arc.

#3

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90o

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Exercises:Exercises:Find the measure of each angle or arc.

#4

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a = 50o

b = 40o

c = 80o

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Exercises:Exercises:Find the measure of each angle or arc.

#5

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d = 80o

e = 140o

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Exercises:Exercises:Find the measure of each angle or arc.

#6

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x = 148o

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Exercises:Exercises:Find the measure of each angle or arc.

#8 - 12

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98o mMN

(

98o mNOM

49o mMPN

64o mMNP

67o mNMP

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Exercises:Exercises:AB bisects CAD, mBD = 95o, and mAD = 74o.

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95o mCAD

84.5o mBCA

47.5o mCAB

85o mCBD( (

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Homework: Practice 8-3A