Transcript 1.4 Measure and Classify Angles

Warm Up
• If RS = 3x + 1, and ST = 15x – 9, RT = 64,
find the value of x. Then find RS, and ST.
1.4 Measure and Classify Angles
• An angle consists of two
different
rays with the same
different rays
endpoint.
• The rays are the sides
side of the
angle. The endpoint
s is the
vertex of the angle.
vertex
• The angle with sides (ray) AB
and (ray) AC can be named
<BAC , <CAB, or <A.
Example: Name Angles
Name three angles is the diagram:
Example: Name Angles
Name three angles in the diagram:
Congruent Angles: Two angles are
congruent angles if they have the exact
same angle
anglemeasure.
measure
Measuring Angles
A protractor
is used to find
the measure
of an angle.
“The measure of angle BAC is 50 degrees.”
Classifying Angles: Copy these into
your
foldable
classification
example
measure range
Angle Bisector
• Write this in your foldable
• A ray that divides an angle into 2 congruent
adjacent angles.
A
D
B
C
BD is an angle
bisector of <ABC.
Angle Addition
Postulate
this of
into
Postulate: write
The sum
theyour
two foldable
smaller angles will
always equal the measure of the larger
angle.
Complete:
M
MRK+ m KRW
m  ____
____ = m  MRW
_____
K
W
R
•
Example: Given the <LKN = 145
degrees, find m<LKM and m<MKN