Chapter 4 - Congruent Triangles

4.1 - Congruent Figures

Congruent figures have the same size and shape.

Congruent polygons have congruent corresponding parts - their matching sides and angles.

When you name congruent polygons, always list corresponding vertices in the same order.

ABC QTR

A Q

B T

C R

AB QT

BC TR

AC QR

R

Given CAT DOG, what can you conclude?

C D

A O

T G

CA DO

AT OG

CT DG

ATC OGD

TCA GDO

Triangles are congruent when they have three pairs of congruent corresponding sides and three pairs of congruent corresponding angles.

Find two congruent triangles:

Theorem 4-1

If two angles of one triangle are congruent to two angles of another triangle, then the third angles are congruent.

A

B

C D

E

F

C F

Can you conclude these figures are congruent?

Find the measure of the missing angles. The two figures are congruent.

Find the measure of the missing angles. The two figures are congruent.

Tell why each statement is true.

Homework

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3 - 13, 16 - 28, 32 - 35