Unit 1B2 Day 5

  Tell whether each statement is needed to show congruence. (yes or no)  The figures must have exactly the same size.  The figures must have exactly the same location.  The figures must have exactly the same shape.  The figures must be triangles.  The figures must be polygons. Do now

  Before, we learned that if all three ____________ and all three _____________ of two triangles are congruent, then _____________________________  But there are easier ways to prove congruence! Triangle Congruence

  If three sides of one triangle are congruent to three sides of a second triangle, then the two triangles are congruent. Side-Side-Side Congruence Postulate (post. 19)

  Prove that Δ ABC ≅ Δ DEC. Ex. 1: SSS

  Prove that Δ PQW ≅ Δ PSW. Ex. 2: SSS

  If two sides and the included angle of one triangle are congruent to two sides and the included angle of a second triangle, then __________________________   _____ is includes between sides _______ and _____ Side-Angle-Side Congruence Postulate (post. 20)

  Ex. 3: Prove that Δ ABC ≅ Δ DEC. Ex. 3: SAS

  Which congruence postulate could you use to prove that Δ ABC ≅ Δ ABD ? Ex. 4: Which Postulate to Use

  Given: CD | AB, CB ≅ BD.  Prove: Δ ABC ≅ Δ ABD. Ex. 5: Which Postulate to Use

  Shared sides or angles – ____________________  X-shape – ___________________  Perpendicular – _________________ Things to Look For

 Closure