You will need your construction tools to copy segments and angles from GEOM Drill 2.12. There are three ways to prove triangles are congruent: the Side-Side-Side Postulate (SSS), the Side-Angle-Side Postulate (SAS), and the Angle-Side-Angle Postulate (ASA). To use these postulates, you must measure either three sides, two sides and the included angle, or two angles and the included side of two triangles.

1. GEOM
You will need your
construction tools today!
Do you remember how to
copy a segment and an
angle?

2. GEOM Drill 2.12? 12/3/12
INCLUDED??????
CA & AR ∠Α IS
INCLUDED
BETWEEN ____
∠R & ∠C & ____
RC IS INCLUDED
A BETWEEN ____
& _____
R
C

3. How do we know two
figures are congruent?
If all corresponding sides
and angles are congruent

4. Objective:
To determine ways to
prove triangles
congruent

5. POSTULATE - SSS POST.
If three sides of one triangle
are congruent to three sides
of another triangle then the
triangles are congruent.

6. POSTULATE - SAS POST.
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.

7. POSTULATE - ASA POST.
If two angles and the included
side of one triangle are
congruent to two angles and the
included side of another triangle
then the triangles are
congruent.

8. To determine if triangles are
congruent, what would you
have to measure?
SSS
SAS
ASA
All sides & all angles.