Geometry 28/29 November, 20121) Place binder and book on your desk.

2) Do Warm Up: (back top)a) What property states that BD = BD?b) What does CPCTC mean?c) Briefly define and sketch median.d) Draw a scalene triangle on patty paper.Construct all three medians by folding to find midpoints, thendrawing in the medians with a pencil.

medianthe segment connecting the vertex

of a triangle to the midpoint of its opposite side

median

Need to come and take test TODAY

P2- Vincent, Jordan, LizethP5- GG

objective

Students will apply triangle properties, triangle congruency shortcuts and CPCTC to do two-column and flow chart proof and explore polygon angle sums.

Students will take notes, work independently and collaboratively and present to the class.

HomeworkDue November 30- sign up for Khan Academy and add me as your coach Choose 5 of the topics listed on the handout and practice until you can get 10 correct (Linear Equations, Linear Functions, Polygons Triangle Congruency, Basic Triangle Proof)Shuttling Around- REVISIONS accepted through November 30th!

MAKE SURE ANY CHANGES ARE EXTREMELY OBVIOUS I don’t have time to re-read your whole project!!

(use different color, notes, etc.)

The Congruence Shortcut Conjectures

SSS correspondence

ASA correspondence

SAS correspondence

AAS correspondence

HL correspondence

SSA correspondence

AAA correspondence

CPCTC… If two triangles are congruent, then Corresponding Parts of those Congruent Triangles are

Congruent CPCTC You must make sure you have CORRESPONDING PARTS SAME RELATIVE POSITION!!!HINTS– Use colored pencils to mark corresponding parts. Mark all info you know on the figure. Redraw triangles separately, and facing the same direction. Extend lines or draw additional lines to make triangles. Use ARROWS.Finish Classwork? END OF CLASS VIDEOhttp://www.youtube.com/watch?feature=endscreen&v=_L8u8io6n2A&NR=1

1. Mark known information on a sketch.2. Start by writing the given information.3. Write what you are trying to prove or show

on the right.4. Fill in the other boxes working backwards

and forwards as needed.ASK:what do I need to know in order to claim the conclusion

is true?what must I show to prove the intermediate result?

Flow Chart Proof

Proofs– HOW?

See page 237- 238See example A- paragraph proof example B- flowchart proof

Compare the paragraph proof in Ex. A with the flowchart proof in Ex. B.

What similarities and differences are there? What is the advantage of each format?

Finish Two Column Proof Handout

Finish handout from yesterday. Think- work silently for 5 minutes Pair- check with a partner Share- whole class discussion

FINISH 4.6 handout, CPCTC 1 – 9, 12

PolygonsThe word

‘polygon’ is a Greek word.

Poly means many

and gon means angles.

Polygons

Polygons

• The word polygon means “many angles”

• A two dimensional object

• A closed figure

More about Polygons• Made up of three or more

straight line segments• There are exactly two sides

that meet at each vertex• The sides do not cross each

other

Polygons

Examples of Polygons

Polygons

These are not Polygons

Polygons

Terminology

Side: One of the line segments that make up a polygon.

Vertex: Point where two sides meet.

Polygons

Vertex

Side

Polygons

• Interior angle: An angle formed by two adjacent sides inside the polygon.

• Exterior angle: An angle formed by two adjacent sides outside the polygon.

Polygons

Interior angle

Exterior angle

Polygons

WRITE THIS IN YOUR NOTES

Interior angle

Diagonal

Vertex

Side

Exterior angle

Polygons

An exterior angle of a polygon is formed by extending one side of the polygon.

Angle CDY is an exterior angle to angle CDE

Exterior Angle + Interior Angle of a regular polygon =1800

DEY

B

C

A

F

12

Polygons

1200

1200

1200

600 600

600

Polygons

Is there a connection between the number of sides,

the number of triangles and

the sum of the measures of the angles in a polygon?

Work with your group to complete Polygon Angle Sum Measures

Polygons

No matter what type of polygon we have, the sum of the exterior angles is ALWAYS equal to 360º.

  Sum of exterior angles = 360º

Polygons

Term Definition Example

Polygon Sum

Conjecture

The sum of the measures of the interior angles of an

n-gon is

Sum of interior angles

Exterior angle sum conjecture

For any polygon, the sum of the measures of a set of external

angles is 3600

Equiangular Polygon

Conjecture

Each interior angle of an equiangular n-gon

Polygons

0180 2n 0180 2n

0180 2n

n

0180 2n

n

debriefWhat patterns did you notice with polygon interior angles?

What patterns did you notice with polygon exterior angles?