1. Angles and Their Measures
Chapter 1 Section 1.4
Angles and Their Measures

2. • Angle: Composed of two rays that have the same initial point B
Vertex
Exterior
Sides
Interior
The angle can be named by
BAC, CAB, or A

3. Name the 3 angles in the picture
PQS Top angle
SQR Bottom angle
PQR Whole angle

4. Congruence  Two angles are congruent if they have the same measure
If ABC  PQR then mABC = mPQR
Two segments are congruent if they have the same measure
Congruence: Having the same size and shape

5. Protractor Postulate A protractor is used to measure angles
Angles are measured using Degrees

6. Angle addition postulateR • T P
RST
RSP
PST
If P is in the interior of RST then
mRSP + mPST = m RST

7. 4 angle types A A Acute Angle Right Angle 0° < mA < 90 °• A A
Straight Angle
mA = 180 °
Obtuse Angle
90° < mA < 180 °

8. m TMF = m TMW + m WMF
m TMF =
m TMF = 90
m XLV = m XLC + m CLV
m  XLV =
m  XLV = 142

13. HW #5 Pg 28: 1-39, 51-58, 64-73