8-1 Congruent Triangles

If 2 triangles are congruent, then corresponding sides and angles are congruent. The converse is true, also.

Example 1

Angle C is congruent to angle Y.

8-2 Proving Triangles Congruent

SSS: Side, Side, Side: If all 3 sides of 1 triangle ar econgruent to all 3 sides of another triangle, then the triangles are congruent by SSS.

SAS: Side Angle Side: If 2 sides and the included angle of 1 triangle are congruent to 2 sides and the included angle of a 2nd triangle, then the triangles are congruent.

ASA: Angle Side Angle: If 2 angles and the included side of 1 triangle are congruent to 2 sides and the included side of another triangle, then the triangles are congruent.

AAS: Angle Angle Side: If 2 angles and the nonincluded side of 1 triangle are congruent to 2 angles and the nonincluded side of a 2nd triangle, then the triangles are congruent.

Example 1: Write a congruent statement and the reason if the triangles are congruent.

SSS - Triangle ABC is congruent to triangle FDE.

8-2 Day 2

Example 2:

Given: Segment AB is congruent to Segment CD, Segment AB is parallel to Segment CD.

Prove: Triangle ABD is congruent to Triangle CDB.

Statement

1. Segment AB is congruent to Segment CD, Segment AB is parallel to Segment CD.

2. Segment BD is congruent to Segment BD.

3. Angle ABD is congruent to Angle BDC.

4. Triangle ABD is congruent to Triangle CDB.

Reasons

1. Given

2. Reflexive

3.

4. SAS

Problem 8-1

What is the reason for statement 3? A- Alternate Interior Angles

B- Exterior Angles are congruent

C- Definition of Congruent Angles

Site hosted by Angelfire.com: Build your free website today!