Download Lesson 4.4:

Lesson 4.4:
1. Homework Discussion
2. Proving Triangles Congruent
3. Shortcuts
Warm Up #1:
• Determine the measure of the missing angle.
Warm Up #2:
• Arrange the unknown measures from greatest
to least.
Post Quiz Problem:
• Find the measure of each lettered angle.
Congruence:
• Two figures are congruent if they have the same size and the same shape.
Therefore, both the corresponding sides and the corresponding angles
must be congruent for the figures to be congruent.
Naming Congruent Parts:
• First, identify all congruent, corresponding parts. Then, write a
congruence statement for the triangles.
Third Angles Theorem:
Why is this reasonable???
Shortcuts:
•
There are 6 different ways that three corresponding parts of two triangles may be
congruent. Some of these will be acceptable shortcuts and some will not.
Testing SSS:
• Investigation #1:Use the handout to complete the
investigation.
• SSS Congruence Conjecture: If the three sides of
one triangle are congruent to the three sides of
another triangle, then ____________________.
Testing SAS:
• Investigation #2:Use the handout to complete the investigation.
• SAS Congruence Conjecture: If two sides and the included angle of
one triangle are congruent to two sides and the included angle of
another triangle, then ____________________.
Testing SSA:
• Investigation #3:Use the handout to complete the
investigation.
• SSA Congruence Conjecture:
Practice:
Practice:
Homework:
• P. 224-226: 2, 4-8, 12, 13, 15, 16, 26a