1.1 Getting Started1.1 Getting Started

Terms to know!Terms to know!

PointsPoints

• A specific place in space.

• Labeled by a capital letter.

• A specific place in space.

• Labeled by a capital letter.

A BC

LinesLines

• Two points connected with a straight line

• Made up of many points (must have 2 points to determine a line)

• Contains arrows at both ends• Goes on into infinity• Labeled by a lower case letter or by 2

points

• Two points connected with a straight line

• Made up of many points (must have 2 points to determine a line)

• Contains arrows at both ends• Goes on into infinity• Labeled by a lower case letter or by 2

pointsA B

mAB

Give all possible names for line l

Give all possible names for line l

A B C Dl

AB

AC

AD

BC BD CD

Line SegmentLine Segment

• Made up of 2 points on a number line but has a beginning and an end.

• Labeled by the two end points in either direction.

• Symbol does not have arrows at the end.

• Made up of 2 points on a number line but has a beginning and an end.

• Labeled by the two end points in either direction.

• Symbol does not have arrows at the end.X Y

XY YX

• On the number line, name the line segment for the section between 1 and 3

• Between 0 and -1• Between 2 and 4• Between -1 and 3

• On the number line, name the line segment for the section between 1 and 3

• Between 0 and -1• Between 2 and 4• Between -1 and 3

10-1 2 3 4

A B C D E F

CE

BA

DF

AE

RayRay

• Has a beginning point but no end point.

• Named by the beginning point then any other point.

• Goes on forever in one direction.

• Has a beginning point but no end point.

• Named by the beginning point then any other point.

• Goes on forever in one direction.

A B C AB or AC

AngleAngle•Two rays with a common start point.

•Vertex: name of the common point.

•Sides formed by the rays.

•Named by numbers or letters.

•Middle letter is always the vertex.

•Can be named by vertex when only one angle present.

A

B

C

<B

<ABC

<1

1

Name all of the angles below:

B

C

A

D

21

<ADB<ADC<BDC

<1<2

∆Triangle

•A triangle has 3 segments as its sides.

•A triangle has 3 angles.

•Written as BOX.

•A triangle is the union of three segments (symbol: U ).

B

OX

BOX = BO U OX U XB

Intersection The intersection of any two sides is the vertex.

CAT

CA AT = A

C A

T