1.3: Angles - Angles and segment addition postulate

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1.3 Angles- Angles and segment addition
postulate
GSE
M(GM)102 Makes and defends conjectures,
constructs geometric arguments, uses geometric
properties, or uses theorems to solve problems
involving angles, lines
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Angle Addition Postulate

• If R is in the interior of PQS, then
• m PQR m RQS m PQS.

P
R
30
20
Q
S
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Find the mlt CAB
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Example of Angle Addition Postulate
100
Ans x40 3x-20 8x-60 4x 20
8x 60 80 4x
20 x
60
40
Angle PRQ 2040 60 Angle QRS 3(20) -20
40 Angle PRS 8 (20)-60 100
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Find the mlt BYZ
-2a48
4a9
4a9
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Segment Addition Post.

• If B is between A C, then
• AB BC AC.

C
B
A
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Write a mathematic equation for the diagram above
using The segment addition postulate.
What would the equation look like now?
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A flight from PVD to NY is 143 miles A flight
from PVD to Washington DC is 355 miles A flight
from NY to Washington DC is _____ miles
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Seg. Add. Post. Example

• If J is between H and K and HJ5x-3 , JK
  4x, HK 8x, find HJ, JK, HK
• Ans Draw a diagram

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Example

• M is between L and N. Find each measurement if
  LM 4x6 ,
• LN 5x10
• MN
  3x 4

LM MN LN
LM 4(4)6 22 MN 3(4)-4 8 LN 5(4)10 30
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Ex if DE2, EF5, and DEFG, find FG, DF, DG,
EG.
D
E
F
G
FG2 DF7 DG9 EG7
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Assignment