geometry unit 2 topic 1

set

a collection of elements

elements

symbols,letters,numbers

how many kinds of sets are there

3

what are the three kinds of sets

finite

infinite

empty

finite set

set that has accountable number of elements {a,3,b,f}

infinite set

Set that has an uncountable number of elements {1,2,3,4.......}

Empty set

A set with no elements shown by the symbol { } or Ø

point

A location in space

The point is represented by

on the dot

A point is named by:

capital letter .A

A point has no

Length, width, or thickness

Line

A infinite set of points that extends endlessly in both directions

Two point create a

Line

There are a ________________ amount of points ON a line

Infinite

How line could be named in two ways

1. Capital letters : AB

2.lowercase letter(cursive)

Plane

A set of points, that forms a completely flat surface, extending indefinitely in all directions

A Plane has no

Boundaries

A plane could be named in two ways

1. Capital letters: (ABC) must be 3 letters

2. one lowercase letter(cursive)

Collinear

Three or more points that lie on the same straight line

Noncollinear

Three or more points that do not lie on the same straight line

Line segment

Subset or part of a line

A line segment is a set of points consisting of

Two points on a line called endpoints

We name a line segment by its

End points

Line segment when named can be

reversed: AC or CA

Midpoint

The point on a line segment of divides the segment into two congruent parts

Line bisector

Any line or subset of a line that intersects a segment at its midpoint

Bisect means to

Cut in half

Whatever comes after the word bisect is the thing that

Is getting cut in half

Ray

A part of a line that consists of a point on the line, called an endpoint as well as all the points on one side of the endpoint

Rays go on forever in

One direction

When naming a ray, what must come first

The endpoint

A point on a line creates

Two opposite rays

Two opposite rays create

A straight line

Addition and subtraction of segments

A line segment is the sum of two line segments within the line segment