Download 1.4 Measure and Classify Angles

1.4 Measure and Classify Angles
Definitions

Angle – consists of two different rays with
the same endpoint.
The rays are the sides of the angle.
The endpoint is the vertex of the angle.
B
vertex
sides
A
C
This angle can
be named BAC
or CAB or A.
Classifying Angles

Acute Angle: less than 90º
A

Right Angle: equals 90º
B

Obtuse Angle: more than 90º

Straight Angle: equals 180º
C
D
Angle Addition Postulate

If P is in the interior of RST, then
m RST = m RSP + m PST
R
P
S
T
Congruent Angles

Two angles are congruent if they have the
same measure.
24º
A
m A = m B so
24º
B
A =~ B