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Prove Triangles Congruent by ASA & AAS. Lesson 4.10 (M1) Use two more methods to prove triangle congruence. Vocabulary. A flow proof uses arrows to show the flow of a logical argument.
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Prove Triangles Congruent by ASA & AAS Lesson 4.10 (M1) Use two more methods to prove triangle congruence
Vocabulary • A flow proof uses arrows to show the flow of a logical argument. • ASA Congruence Postulate: If two angles and the included side of one triangle are congruent to two angles of a second triangle, then the two triangles are congruent • AAS Congruence Theorem: If two angles and a non-included side of one triangle are congruent to two angles and the corresponding non-included side of a second triangle, then the two triangles are congruent.
In the diagram at the right, what postulate or theorem can you use to prove that ? Explain. RSTVUT STATEMENTS REASONS Given S U Given RS UV The vertical angles are congruent RTSUTV for Examples 1 and 2 GUIDED PRACTICE SOLUTION
RTSUTV for Examples 1 and 2 GUIDED PRACTICE ANSWER Therefore are congruent because vertical angles are congruent so two pairs of angles and a pair of non included side are congruent. The triangle are congruent by AAS Congruence Theorem.
ABC GIVEN m 1 + m 2 + m 3 = 180° PROVE STATEMENTS REASONS 1. Parallel Postulate 1. Draw BDparallel to AC. 2. m 4 + m 2 + m 5 2. = 180° Angle Addition Postulate and definition of straight angle , 4 3. 1 5 3. 3 Alternate Interior Angles Theorem m 4 m 5 4. m 1 = , m 3 = 4. Definition of congruent angles 5. m 1 + m 2 + m 3 5. Substitution Property of Equality = 180° for Examples 1 and 2 GUIDED PRACTICE