Download 6-1 Notes File

6-1 Sums and Differences in Geometry!
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Supplementary Angle Defn:
2 angles that add up to 180º
x
Complementary Angle Defn:
2 angles that add up to 90º

y
x
y
x + y = 180º
x + y = 90º
------------------------------------------------------------------------------------Triangle Sum Theorem:
A triangle that has angle measures a, b and c … a + b + c = 180º
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Solve by using GREAT Chicago Math steps… Thanks! 
If x + y = 180
and x = 83.7º…
Find y
Find the measure of
the 3rd angle of a
triangle if the other
two angles are 32° and 123º
2 x
a + b + c = 180°
a + b + c = 180°
a + 32 + 123 = 180
2x + 40 + 90 = 180
a + 155 = 180
- 155 - 155
2x + 130 = 180
- 130 -130
90
40
x + y = 180
83.7 + y = 180
-83.7
-83.7
y = 96.3°
2x = 50  x  25
2
2
---------------------------------------------------------------------------------------------------------The measures of a triangle are c, 2c
A triangle… 2 angles are the same
and 3c. Find the ACTUAL measure
and the third is 30° more than either
of ALL the angles!!!
of them…Find ALL of the angles…
a = 25°
a + b + c = 180°
c + 2c + 3c = 180°
1c + 2c + 3c = 180
6c = 180
6
6
c = 30°