4-2+Congruent+Triangles+Part+II

= = **Congruence & Triangles**

In section 4.2 You will learn how to Identify congruent figures and corresponding parts. You will also learn how to prove triangles are congruent.

**__Vocabulary:__**
 * ** Congruent ** - same size and shape. Corresponding angles and sides are congruent.
 * ** Corresponding Angles ** - two congruent angles, both lying on the same side of the transversal and situated the same way on two different parallel lines.
 * ** Corresponding Sides ** - when the position of two sides is the same in two figures.

** __Thermos:__ **


 * ** Third Angles' Theorem ** - If two angles of one triangle are congruent to two angles of another triangle, then the third angles are also congruent.
 * ** Reflexive Property of Congruent Triangles ** - every triangle is congruent to itself.
 * ** Symmetric Property of Congruent Triangles - ** If triangle ABC is congruent to triangle DEF, then triangle DEF is congruent to triangle ABC.



These two triangles are congruent to each other because line AB is congruent to line AB1, line BC is congruent to line BC1, and line AC is congruent to AC1.



These Triangles are congruent to one another because angle C is congruent to angle C1, angle A is congruent to angle A1 and line AB is congruent to line AB1.

ASA congruence

These two triangles are congruent because angle ABC in congruent to angle DBC, Angle ACB is congruent to angle DCB, and line CB is congruent to itself.

**Problem :** Can you prove triangle ABC congruent to triangle DEF? If so, by which method can you show that they are congruent?

**Problem :** Can you prove triangle ABC congruent to triangle DEF? If so, by which method can you show that they are congruent?

**Problem :** Is triangle ABC congruent to triangle DEF? If so, by which method can you show that they are congruent?

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