Download 8.1 Building Blocks of Geometry

6.4.2 I can describe figures by using the terms of
geometry
Vocabulary
point
line
plane
line segment
ray
Use the diagram to name the geometric figure.
A. three points
B. two lines
U
V
W
T
S
Use the diagram to give a possible name to the
figure.
A. three different
line segments
A
B
C
B. three ways to name the line
Lesson Quiz
Use the diagram to name each geometric
figure.
Possible answer: A,
1. three points B, C
2. two lines
Possible answer: AD, CE
3. a point shared by a line and
Possible answer: F
a ray
4. a plane
Possible answer: plane AEC
6.4.2 I can name, measure, draw, and classify angles
Vocabulary
angle
vertex
acute angle
right angle
obtuse angle
straight angle
An acute angle measures
greater than 0° and less than
90°.
A right angle measures
exactly 90°.
Reading Math
Right angles are usually marked with a
symbol.
An obtuse angle
measures greater
than 90° and less
than 180°.
A straight angle
measures exactly
180°.
Additional Example 3: Classifying Angles
Classify each angle as acute, right, obtuse, or straight.
A.
The angle measures
less than 90°, so it is an
acute angle.
B.
The angle measures
exactly 90°, so it is a
right angle.
Check It Out: Example 3
Classify each angle as acute, right, obtuse, or straight.
A.
The angle measures
less than 90°, so it is an
acute angle.
B.
The angle measures
exactly 180°, so it is a
straight angle.