7.3 Activity: Discovering A Similarity Postulate

• Draw triangle ABC with m<A = 60 and

m<B = 40

• Draw another triangle DEF with m<D =60 and m<E = 40, and DE > AB.

• Copy and complete the chart below: ABC DEF Ratio

AB = ? DE= ?

BC = ? EF = ?

CA = ? FD = ?

Warm-up

• How many of your brackets are busted?

TodayWarm-upDiscuss quizObjectiveGuided notesExample problems

“Have more than you show, speak less than you know.” –William Shakespeare, King Lear

Chapter 7

7.3-7.4 Similar Polygons

Obj: _______________________

____________________________

Angle-Angle (AA) Similarity Postulate

• If the angles of one triangle are congruent to the angles of a second triangle, then the triangles are similar.

If <K = <Y

and <J = <X

Then, KLJ ~ YZX

K Y

X Z

J L

USING SIMILARITY THEOREMS

THEOREM S

THEOREM 8.2 Side-Side-Side (SSS) Similarity Theorem

If the lengths of the corresponding sides of two triangles are proportional, then the triangles are similar.

If = =A BPQ

BCQR

CARP

then ABC ~ PQR.

A

B C

P

Q R

Warm-up• Have your notes out and ready to go.

• Grades are up to date on HAC make sure you have everything turned in.

TodayWarm-upGuided notesHomework problems

“Have more than you show, speak less than you know.”

–William Shakespeare, King Lear

USING SIMILARITY THEOREMS

THEOREM S

THEOREM 8.3 Side-Angle-Side (SAS) Similarity Theorem

If an angle of one triangle is congruent to an angle of a second triangle and the lengths of the sides including these angles are proportional, then the triangles are similar.

then XYZ ~ MNP.

ZXPM

XYMN

If X M and =

X

Z Y

M

P N