1.3

What is it Called?Pg. 9

Common Vocabulary Words for Geometry

1.3 – What is it Called? _____________Common Vocabulary Words for Geometry

Today you are going to develop your vocabulary for geometry. There are many different words that can be used to describe shapes. Sometimes these words have a definition, and sometimes they are undefined.

1.16 – UNDEFINED TERMSWhen does a word not have a definition? How will you know what the word means if there is not a specific definition? Examine these questions as you answer the following:

Term Picture Description Notation

Point    

____ capital letter

Adot

1

Point A

Term Picture Description Notation

Line    

____ capital letters

Both ends go on forever, made of infinite points

2

AB BA

A BC

AC CA

BC CB

Term Picture Description Notation

Collinear points    

Points that line up

Points A, B, and CA B

C

Term Picture Description Notation

Plane    

A

B C

X

A flat surface extending in all directions

3 letters

Plane ABC

1 letter

Plane X

Term Picture Description Notation

Coplanar points    

Points on the same plane

A

B C Points A, B, and C

X

1.17 – GROUP ROTATIONYou are now going to work with your group to round robin. Each set of tables will have a new piece of information for your group to gather. Each rotation will only be 7 minutes long. As you work today, make sure that your team uses the group roles.

TEAM CAPTAIN: Keep track of time. Do not remain on any one question for too long, or you will run out of time. Make sure everyone is completing their team responsibilities and is staying on task.

RESOURCE MANAGER: Make sure any supplies are being shared and used by everyone. Call the teacher over if no one is sure of how to approach the question.

FACILIATOR: Make sure your group is taking turns on reading the questions. If someone seems to be confused or not understanding, make sure the group helps them.

RECORDER: Make sure everyone has the same answer to the one agreed upon. If not, make sure the person(s) are aware of the difference. Make sure everyone has the answer before moving on to the next question.

Group #1 AGroup #2 BGroup #3 CGroup #4 DGroup #5 EGroup #6 FGroup #7 GGroup #8 H

1.18 –VOCABULARY FROM TODAYToday you learned a bunch of vocabulary that is essential for your understanding of the course. Please add the definition of each of the vocabulary words you used today along with any notation that goes along with it.

Term Picture Description Notation

Ray    

____ capital letters

AB

C D

Initial point, then continues in one direction

2

AB

DC

Term Picture Description Notation

Opposite Rays    

AB

C

Rays that go in opposite directions

AB

AC

and

Term Picture Description Notation

Segment    A

BHas two endpoints, doesn’t go on forever

AB

BA

Term Picture Description Notation

Congruent    A

B

CD

Same shape and size AB CD

Term Picture Description Notation

Parallel    

C

DA

B Lines that don’t touch AB CD

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Term Picture Description Notation

Perpendicular    A B

C

D

Lines that cross at right angles

AB CD���������������������������������������� ���

For a-g, use the picture on the right. Make sure to use correct notation.

a. Name two segments shown.

AN�������������� �

CM�������������� �

Point N

Points A, N, and X

c. Name three collinear points.

Plane ANC

d. What are two other ways to name plane V?

Plane MNX

No

e. Are points R, N, M, and X coplanar?

f. Name two rays shown in the figure.

NA��������������

NC��������������

NM��������������

1.19 –PROPERTIES OF VOCABULARYDetermine whether each statement is always, sometimes, or never true. Draw a picture to support your answers.

Never

Sometimes

17. A plane contains only three points

Never

Always

19. If three points are on the same plane, they are on the same line.

Sometimes

Never