11/3/2013

1

To prove that two triangles are congruent, we learned in sect 4.2 that we have to know that all corresponding angles and sides have to be congruent.

Today, we will learn two Postulates that can help us to identify congruent triangles without having to identify every side and angle congruent.

11/3/2013

2

If three sides of one triangle are congruent to three sides of a second triangle, then the two triangles are congruent.

If and

then

,, RSNPQRMN

QRSMNP

M

N

P

Q

S

R

,SQPM

If two sides and the included angle of one triangle are congruent to two sides and the included angle of a second triangle, then the two triangles are congruent.

If

XYQS

XQ

WXPQ

,

,WXYPQS

S

S

A

P

Q

S

W

X

YS

11/3/2013

3

11/3/2013

4

Copy a Triangle construction pg. 213