Chapter 1: Introduction to Geometry

Section 1.1 - Getting Started

Points

have no dimensionrepresented by dotsnamed using capital lettersexamples:

A B

CD

E

Linesone-dimensionalmade up of points and extend infinitely

in both directionsnamed using a single, lowercase, cursive

letter or named by two points on the linesymbol:examples:

A

B m

AB BAline m

Line Segmentsone-dimensionalmade up of points and terminate at two

endpointsnamed using the two endpointssymbol:examples:

MN

M N

NM

Raysone-dimensionalbegin at an endpoint and extend

infinitely in only one directionnamed using the endpoint first, then

another point on the raysymbol:example:

YXW X Y

YW

Angles• formed by the union of two rays with a

common endpoint (the vertex)• three ways to name an angle:1) using the vertex and a point on each ray of

the angle

2) using just the vertex

3) using a number L N

M

6

MLN or NLM

L

6

Triangles

the union () of three line segments

the intersection () of any two sides is a vertex of the triangle

B C

A

CABCABABC

BBCAB

Practice C

B

E

D

A

AC EAEC CEAor

E DBAC

ABDC

BCAB B BCBA ABC

Practice 1.1

Section 1.1Assignment

Pgs. 7-8: #5-12

Note: You should draw diagrams for problems that have diagrams.