BellringerDiscuss with your shoulder partner the

following situation…

Why does a four-legged chair sometimes wobbles, but a three legged chair never wobbles???

Points, Lines, and Planes

Objective:I will represent simple geometric shapes

like points, lines, segments, rays, and angles using proper identification.

PointPDrawn: as a dotNamed by: a CAPITAL letterFacts: A point has neither shape nor sizeWords/Symbols: point P

Line

AB

n

Drawn: with an arrowhead at both endsNamed by: the letters representing two points on the line or a lowercase script letterFacts: There is exactly one line through any two points

Words/Symbols: line n, line AB or , line BA or

AB

BA

VocabularyCollinear-Noncollinear-

Plane

X

Y

Z

T

Drawn: as a shaded, slanted 4-sided figureNamed by: a capital script letter or by the letters naming three noncollinear pointsFacts: There is exactly one plane through any three noncollinear points

Words/Symbols: plane T, plane XYZ, plane XZY, plane YXZ, plane YZX, plane ZXY, plane ZYX

PlaneParallel Planes: Planes that do not intersect

Examples in Real Life

Write Rally RobinStudents take turns stating and writing

responses or solutions. Record answers on one sheet of paper.

Name the line of intersection

Point, Line, Plane Video

Partners take turns, one solving a problem while the other coaches.

1. Partner A solves the first problem.2. Partner B watches and listens, checks,

coaches if necessary, and praises.3. Partner B solves the next problem.4. Partner A watches and listens, checks,

coaches if necessary, and praises.

Rally Coach

Draw and label a figure for each relationship.Plane R contains lines AB and DE, which

intersect at point P. Add point C on plane R so that it is not collinear with AB or DE

QR on a coordinate plane contains Q(-2,4) and R(4,-4). Add point T so that T is collinear with these points.

Space- a boundless, three dimensional set of all points. Space can contain lines and planes

nm

lF

T U

R S

P Q

W

1. Name a line that contains point P.2. Name the plane containing lines n and m.3. Name the intersection of lines n and m.4. Name a point not contained in lines l, m, or n.5. What is another name for line n?6. Does line l intersect line m or line n? Explain.

In review…There are 3 basic terms in geometryPoint, Line, and PlaneHow do we model them?Draw them?Name them?And write them?

It’s important…