Download Chapter 1.4

Chapter 1.4
Angle Measure
Vocabulary
 Ray – part of a line that has one endpoint and
extends indefinitely in one direction.
 Opposite Rays – two rays that share a
common endpoint and are collinear
 Angle – formed by two noncollinear rays
(sides) that share a common endpoint
(vertex). There is an interior of each angle
and an exterior of each angle.
Example 1
Angles and Their Parts
A. Name all angles that have B
as a vertex.
Answer:
Example 1
Angles and Their Parts
B. Name the sides of 5.
Answer:
Example 1
C.
Angles and Their Parts
Example 1a
A.
B.
C.
D.
Example 1b
A.
B.
C.
D.
none of these
Example 1c
Which of the following is another name for 3?
A.
B.
C.
D.
Concept
Measure and Classify Angles
A. Measure TYV and classify it as right,
acute, or obtuse.
Answer: mTYV = 90, so TYV is a right angle.
Measure and Classify Angles
Answer: 180 > mWYT > 90,
so WYT is an obtuse angle.
Measure and Classify Angles
Protractor Time!
 Measure an angle
 Create an angle
Measure and Classify Angles
INTERIOR DESIGN Wall stickers of standard shapes are often
used to provide a stimulating environment for a young child’s
room. A five-pointed star sticker is shown with vertices labeled.
Find mGBH and mHCI if GBH  HCI, mGBH = 2x + 5, and
mHCI = 3x – 10.
Find mBHC and mDJE if BHC  DJE,
mBHC = 4x + 5, and mDJE = 3x + 30.
A.
mBHC = 105, mDJE = 105
B.
mBHC = 35, mDJE = 35
C.
mBHC = 35, mDJE = 105
D.
mBHC = 105, mDJE = 35