9/12 Bell RingerStep 1: Name angles 1, 2, 3 and 4 in three

different ways each.

DGC

RA

B

SX12

3 4

9/12 News and Notes

• Syllabus Status

• Exit Slip Grades

• Announcements: Quiz 1.1 on Friday– Covering all material up to this point

9/12 Agenda

SWBAT identify collinear and coplanar points, parallel and perpendicular lines.

- Do Now Review- Exit Slip Review

1. General Word Knowledge

2. 1 Example – Writing geometry sentences

3. Guided Practice – Convert the following to geometry sentences!

4. Independent Practice

New Material

• Today we will talk more about point and line relationships in 2-D space.

• What does it mean for two teachers to be coworkers?– Work together– Work on the same projects, do similar things.

New Material, cont.

• Based on your understanding of what a coworker is, write down your own definition of what it means for 2 points to be collinear:– 2 points are collinear if they’re on the same

line.

• Now write down what you think it means for two points or lines to be coplanar:– 2 points or lines are coplanar if they’re in the

same plane.

New Material, cont.

• Now think back to the Chicago Map. Recall that it is set up like a coordinate plane.

• Do Ashland and Loomis ever intersect (cross each other)?

• So what are they?– PARALLEL LINES NEVER INTERSECT

New Material, cont.

• What about Roosevelt and Loomis? How do they intersect?– They intersect at right angles

• Two angles that intersect at a 90° angle are PERPENDICULAR LINES.

1 Example

• Give examples of:

• Collinear points

• Coplanar points

• Non-collinear points

• Non-coplanar points

A

D

B

C

E G F

H K J

XR

1 Example

• Give examples of:

• What lines are // ?

EF // HJ

• What lines are ?

EF GK and HJ GK

A

D

B

C

E G F

H K J

XR

Now write a sentence that details the relationship between elements

• EF and HP• In words:

EF is parallel to HP

• In math notation:

EF // HP

A

D

B

C

ER F

HK P

OT

Now write a sentence that details the relationship between elements

• EF and RK• In words:

EF is perpendicular to RK

• In math notation:

EF RK

A

D

B

C

ER F

HK P

OT

Now write a sentence that details the relationship between elements

• R and H

R and H are coplanar• T and K

T and K are noncoplanar• H and K

H and K are collinear

A

D

B

C

ER F

HK P

OT

• P and E

P and E are noncollinear

Independent Practice

• You now have time now to work on the Independent practice portion of the work.

EXIT SLIP Answer on a sheet of loose leaf

L

M

J K

N O

P

S

Q

R

T

1.) Give an example of perpendicular lines, using geometric notation.

2.) What is the relationship between points O and P?

3.) Describe the relationship between points K and O (hint: there are two answers for this).

4.) Which lines are parallel to each other? (Use geometric notation to describe.

5.) What type of angle is formed at a perpendicular intersection?