Download Unit 1 - Lesson 1.2c - Basic Definitions of Geometry

Geometry
Name: _______________________________
Unit 1: Lesson 1.2c
Date: _________________ Period: _______
Basic Definitions of Geometry – Angles
Essential Questions:
o
Why is it important to use a conventional method for naming and notating points, lines, segments,
rays, angles, and planes?
Goal:
 I will discover angles using different varieties of notation.
 I can understand the Angle Addition Postulate and the Segment Addition Postulate are based on the
same principle.
Key Ideas/Vocabulary:
ANGLES:
A figure formed by two ________ that have the same _______________.
The two rays of the angle are called the _________________.
Their common endpoint is called the _____________.
Notation: ______________ (For example: __________ or ____________)
CLASSIFICATION OF ANGLES:
ACUTE ANGLE: measure between ___________ and ____________
RIGHT ANGLE: measure __________
OBTUSE ANGLE: measure between _________ and ____________
STRAIGHT ANGLE: measure adds to __________
CONGRUENT ANGLES: are angles that have ______________ measures.
ADJACENT ANGLES:
are two angles in a plane that have a common vertex and a common side by no
common interior points.
POSTULATE: proven ________ that justify the ways and development of geometry.
ANGLE ADDITION POSTULATE: If C is the interior of AOD , then m AOC  m COD  m AOD .
Section 1: Angles and Their Parts
1) Refer to the figure.
a.) Name all angles that have B as a vertex.
b.) Name the sides of  5 .
c.) Write another name for  6.
Answer: a.) ______________________ b.)_____________________c._____________________
YT1) Refer to the figure.
a.) Name all angles that have X as a vertex.
b.) Name the sides of  3 .
c.) Write another name for  3.
Answer: a.) ______________________ b.)_____________________c._____________________
Section 2: Measure and Classify Angles
2) Measure each angle named and classify it as
right, acute, or obtuse.
YT 2) Measure each angle named and classify it as
right, acute, or obtuse.
a.)  XYV
a.)  CZD
Answer:
3) Measure each angle named and classify it as
right, acute, or obtuse.
Answer:
YT 3) Measure each angle named and classify it as
right, acute, or obtuse.
b.) WYT
b.)  CZX
Answer:
4) Measure each angle named and classify it as
right, acute, or obtuse.
Answer:
YT 4) Measure each angle named and classify it as
right, acute, or obtuse.
c.) TYU
c.)  DZX
Answer:
Section 3: Angle-Addition Postulate
Answer:
5) Solve.
YT 5) Solve.
Answer:
6) Solve.
Answer:
YT 6) Solve.
Answer:
Answer:
Homework:
Angles – Supplement Worksheet # 4
Lesson Summary:
mWVX =__________ mZVY =__________
A railroad crossing sign forms congruent angles. In the figure, mWVX  mZVY .
If mWVX = 7a + 13 and mZVY = 10a – 20, find the actual measurements of each.
Name______________________________________________Period__________Date____________________
ANGLES - SUPPLEMENT WORKSHEET # 4
Also, find angle  3 and  2 .