Draw six segments that pass through every dot in the figure without taking your pencil off the paper.

INF Session 2

Have Your Homework On Your Desk!

Agenda Session 2

• Warm-Up

• Homework ?s

• Finish Notes 1.2

• Notes 1.3 & 1.4

• Practice Work

Tues 8/16 Quiz 1.1 – 1.4

Get textbooks

Thurs 8/18

1.6 & 2.1

Write down textbook name on textbook form.

Geometry Concepts and ApplicationsRED and BLUE

Staple CALCULATOR form on TOP.

Informal Geometry Session 2

Complete 1.2 andbegin 1.3 & 1.4

COPLANAR Pointslie in the same plane

NONCOPLANAR Points

do NOT lie in the same plane

Start 4th period here

• Has a beginning and an end• Name a line segment by using the

endpoints only• You will always use two letters to

name a segment• Symbol or

Segment

Name of this segment:

• Has a beginning but no end• Starting pt. of a ray is called the

endpoint• Name a ray by using the endpt. 1st and

another point on the ray• You will always use two letters to name a

ray• Symbol or

Ray

Names of this ray:

Start 7th period here

What Do You See?

AD

C

B

Points: A, B, C, D

Line: AD

Ray: DB

Segment: BD

Worksheet1.2

• Work quietly with a neighbor• We will go over these

1.3 Postulates

• Postulates are facts about geometry that are accepted as true.

Postulate 1-1

• Two points determine a line.

• There is only one line that contains points P and Q.

P

Q

Example 1

Points, C, A, and R are noncollinear. Name all the different lines that can be drawn. (Only name a line once.)

Postulate 1-2• If two distinct lines

intersect, then their intersection is a point.

• Lines l and m intersect at point T.

lm

T

Example 2

Name the intersection of .AR and CR

Postulate 1-3

• Three noncollinear points determine a unique plane.

• There is only one plane that contains points A, B, and C.

A

B

C

EXAMPLE 3

H

R l

MF

T

A

W

V

g

TRUE or FALSE: There is only one plane that contains all of the points F,

T, & M

TRUE

EXAMPLE 4

A

F

E D

C

B

G

H

Name all of the planes that are represented in the prism.

Postulate 1-4

• If two distinct planes intersect, then their intersection is a line.

EXAMPLE 5

A

F

E D

C

B

G

H

Name the intersection of plane ABH and plane DCG.

CB

Classwork

•Practice Worksheet 1.3

Conditional Statements• Called if-then statements.• Hypothesis- The part following if.• Conclusion- The part following

then.

* Do not include if and then in the hypothesis and conclusion.

Hypothesis and Conclusion

• If you are not satisfied for any reason, then return everything within 14 days for a full refund.

Try These

• If it is Saturday, then Elise plays soccer.– Hypothesis-– Conclusion-

• If points are collinear, then they lie on the same line.– Hypothesis-– Conclusion-

it is Saturday Elise plays soccer

points are collinear

they lie on the same line

Converse• The converse of a conditional

statement if formed by exchanging the hypothesis and the conclusion in the conditional.

– Conditional- If a figure is a triangle, then it has three angles.

– Converse- If a figure has three angles, then it is a triangle.

* The converse does not have to be true.• Conditional- If a figure is a

square, then it has four sides.• Converse- If a figure has four

sides, then it is a square.

* Not all four sided figures are squares. Rectangles also have four sides.

Rewrite the statement as a conditional statement, then find

the converse.• All members of Congress are U.S.

citizens.

• Conditional-

• Converse-

If you are a member of Congress, then you are a U.S. citizen.

If you are a U.S. citizen, then you are a member of Congress.

Classwork• Practice Worksheet 1.4

–HW finish 1.3 & 1.4 ws

•QUIZ NEXT CLASS!!1.1 – 1.4