Terms, Notation, and Representation

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Naming Real World Examples

Point

An exact location in space with indefinite size and shape

labeled with capital letters

A

A

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Naming Real World Examples

An object with no thickness that extends infinitely far in two directions

Line

X Z l

XZ or ZX

or the lower case script l

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Naming Real World Examples

Line Segmen

t

a piece of a line consisting of two endpoints and all points in between.

E A

the two points are the endpoints of the line and are used to name the line segmentAE or EA

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Naming Real World Examples

Ray

A piece of a line consisting of one endpoint and extends infinitely in one direction

the endpoint of the ray always comes firstAE

A

A

E

E

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Naming Real World Examples

Opposite Rays

Two rays sharing the same endpoint and continuing infinitely in opposite directions

I JT

TJ and TI

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Naming Real World Examples

Plane

a flat surface that extends infinitely in all directions

named in two ways•with a script capital letter M•using any three points that lie in the plane STR

M

S T

R

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Naming Real World Examples

Collinear

Points that lie on the same line

A B C

Points A, B, and C are collinear

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Naming Real World Examples

Non-Collinear

Points that DON’T lie on the same line

A B

C

Points A, B, and C are non-collinear

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Naming Real World Examples

Coplanar

Points that lie on the same plane

M

S T

R

Points S, T, and R are coplanar

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Naming Real World Examples

Non-Coplanar

Points that DON’T lie on the same plane

A

B C

Points A, B, and C are non-coplanar

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Naming Real World Examples

SkewLines

Lines that do not intersect and are not coplanar.

Lines m and n are skew lines.

n

m