Download 1.4 - MrsSicasMathWiki

1.4
Angles
HMWK:
pp. 29 – 31, #s 18 – 28 even, 29 – 34, 38, 39
Game Plan:
Today I will be able use angle postulates and classify
angles.
Warm-up:
Draw 3 collinear points A, B, and C. Draw point D
which is not collinear with A, B, and C.
Draw AB and BD
1.4
Angles
Today …
1.
2.
3.
4.
Check homework
Define & classify angles
Angle addition postulate
Wrap-Up
1.4
Angles
Angles
Sketch an angle.
Exterior B
side
Interior
Vertex
A
C
side
Angle (  ): two rays (sides) with same initial point (vertex)
Congruent Angles ( ) : Same measure.
Interior: between the two rays (inside)
Exterior: not the interior (outside)
1.4
Angles
Angle Addition Postulate
If D is in the interior of BAC, then
mBAD + mDAC = m BAC
B
D
35°
47°
A
C
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Angles
Classifying Angles
Acute:
measure is less than 90°
Obtuse:
measure greater than 90°
Right:
measure IS 90°
Straight:
measure is 180°
1.4
Angles
Wrap-Up
•
TOMORROW BRING …
1. Ruler
2. Protractor
3. Compass