Chapter 1.1Chapter 1.1Chapter 1.1Chapter 1.1

04/21/23

Vocabulary point• line• collinear points• plane• compass• straightedge• sketch• draw• construct

• coplanar lines• skew lines• ray• endpoint of a ray• line segment• endpoints of a line segment• congruent line segments

Basic Geometric Figures

♥ Point♥ Line♥ Plane

Undefined terms:

Point• Location shown by dots, can be

endpoints or corners

HOW TO WRITE: ONE Capital Printed letter such as A or X

A

XB

y

M

W X

YZ

Examples of Points

Lines• All points arranged perfectly straight

with no thickness, and has infinite length.

HOW TO WRITE: • two points on the line, with a double-

headed arrow over the two letters.• a single Lowercase Cursive letter.

A

XB

y

M

yt

AM MX XA

Is B on MY?

Examples of Lines

Intersection

• Symbol example: AB CD = X

U U

A

BC

D

X

Book P.4-5

Plane• A plane is a flat surface that extends

infinitely in all directions.HOW TO WRITE:♥ named by three non-collinear points

that lie on the planeOr♥ It can be named by one Cursive Capital

letter such as D.

A

C

B

SR

ABC

D

Examples of Planes

Book p 7

Collinear♥ Points on the same line

Coplanar♥ Points on the same plane

A B C D

A

C

B

Ray♥ part of a line that starts at a point

and goes forever in one direction. ♥ HOW TO WRITE: Letter under

endpoint must be the start of the ray.

A

BBA

Segment• a part of a line that begins at one point

and ends at another (the endpoints) • HOW TO WRITE:

– The endpoints have a bar over them.

A BBA

C

DCD

Book p.11-15A B

Hatch Marks – short slash markings that show two or more segments are equal in length

W X Y Z

WX = YZ

Congruent - segments that have the same measure (like equal)

~

Urkle Stephon

Zack Cody

Show what you know!