But first a little warm up…

How much do you need to know?

• To prove two triangles are exactly alike? (congruent)

• If all 6 parts (3 corresponding sides and 3 corresponding angles) are congruent….that would do it.

• Any “shortcuts”?

Postulate 19-Side Side Side (SSS) Congruence Postulate

• If three sides of one triangle are congruent to three sides of another triangle

• Then the two triangles are congrurent.

• The remaining parts are congruent.

Side CADOSide CTDGSide ATOG

CAT DOG

G

O

D

T

A

C

Postulate 20-Side-Angle-Side (SAS) Congruence Postulate

• If two sides and the included angle of one triangle are congruent to two sides and the included angle of another triangle…

• Then the triangles are congruent.

Side CADOAngle AOSide ATOG

CAT DOG

G

O

D

T

A

C

Use the diagram. Name the included angle between the pair of

sides given.

For each pair of congruent triangles, name the pairs of

corresponding sides.

Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence

postulate you would use.

Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence

postulate you would use.

Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence

postulate you would use.

Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence

postulate you would use.

Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence

postulate you would use.

Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence

postulate you would use.

Decide whether enough information is given to prove the triangles are congruent. If there is enough information, state the congruence

postulate you would use.

Are these triangles congruent?

• By what rule?

• Could you use the distance formula to verify your claim?

8

6

4

2

-2

-4

-6

-8

-10 -5 5 10

DE

F

C

BA

Assignment 4.3