+

1-1 Points, Lines, and Planes

+Real-Life

+Vocabulary Undefined Terms- point, line, and plane are

considered undefined terms because they are only explained using examples and descriptions

Point- a location – it does not have shape or size (named by capital letter)

Line- made up of points and has no thickness or width (named by a lowercase letter, or two points on the line)

Plane- a flat surface made up of points that extends infinitely in all directions (named by a capital script letter, or 3 points in the plane)

A

m

P QJ .

K .L .

B

+Vocabulary

Collinear- points that lie on the same line

Coplanar- points that lie in the same plane

Intersection- the set of points that two or more geometric figures have in common

Space- a boundless, 3-D set of all points

+Examples

Line g ; or line PN

Line j; or line MT

Plane S; or Plane TNQ

+Practice

Line q

Point B or Point A

Line DC

Plane G or Plane ABD

+Examples 4. Draw and label a figure for AK and CG intersect

at point M in plane T.

5. How many planes are shown?

6. Name 3 collinear points:

7. Are points N, R, S, and W coplanar? Why (not)?

A

K

C

G

M

T

6

SXM

No. NRS all lie on plane A, but W is on plane WTQP

+Practice 4. Draw and label a figure for lines q and f

intersect at point Z in plane U.

5. How many planes are shown?

6. How many of the planes contain points F and E?:

7. Name 4 points that are coplanar:

5

2

FEAB, or EDCB, or CAFD