Warm-ups w P. 869 1-5 no calculators w These problems are due in 3 min.

Warm-ups

P. 869 1-5 no calculators These problems are due in 3 min.

Date

Sec 1-1

Concept: Identify Points, Lines and Planes

Objectives:

Given basic concepts in Geometry, name and sketch geometric figures

3-Undefined Terms in Geometry

Point Line Plane

Undefined. It has no dimension. It is usually represented by a small dot

Point

ALabel with Capital Letters

Line

Undefined Extends in one dimension. Usually represented by a straight line with arrows on the ends.

A Bl

Labels: AB BA l

Plane:

undefined Extends in two dimensions. Usually represented by a shape that looks like a table top.

A

B

C

M

Plane M or plane ABC

Key Terms – you probably already know some of these… Coplanar and Noncoplanar Collinear and Noncollinear Ray Segment Opposite ray Intersect

Collinear: points that lie on the same line

P I G S

Points P, I, G, and S are collinear

Non-Collinear: Points that do not lie on the same line

D

O

G

Points D, O and G are noncollinear

Coplanar: Points that lie in the same plane

Points M, A, T, H, S are coplanar

HT

S

G

M A

Non -Coplanar: Points that do not lie in the same plane

Points G, S and H are non- coplanar

A

HT

S

G

M

Line Segment: Part of a line that consists of 2 endpoints

AB or BA

A B

Ray: Part of a line that consists of a point called the initial point and all points on the line that extend in one direction.

A

B

A is the initial point

AB

Opposite Rays: If C is between A and B, then CA and CB are opposite rays

AC B

Intersect: To have one or more points in common

Intersection: The set of points that two or more geometric figures have in common

C

L

PN M

O

1. Name 3 coplanar points

2. Name 3 collinear points

3. Name 3 non-collinear points

4. Name a line segment in two different ways

5. Name a ray

Example 1:

C

L

PN M

O

6. Name a line in 2 ways

7. Name a point

8. Name the plane in two ways

9. What is the intersection of LO and plane C

Example 1: Cont.

Example 2: Sketch the figure described

A. A line and a plane that do not intersect

B. 2 planes that do not intersect and a line that intersects each plane in 1 point

Example 3: Determine if the point lies on the line

A. Y = x-4 A(5,1)

1 = 5-4

1=1

YES, it lies on the line

B. Y = 2x + 3 A(7, 16)

16 = 2(7) + 3

16 ≠ 17

NO, It doesn’t lie on the line

Example 4: Graph the inequality on the number line. Tell whether the graph is a segment, a ray or rays, a point or a line

X>2 or x<5

0 2 5

Line

Example 5: What kind of Geometric Intersection does the photograph suggest?

The intersection of 2 lines

The intersection of a line and a plane

Today’s Work:

In Class:

Homework: