- Move on to the two- column proofs. Go through the material. Request that the students participate in
completing the proof. - Flow proofs- go through the material.
- If time allows, have students write their own flow proofs and share them in small groups. You could also
assign this as a homework assignment.
III.SpecialNeeds/Modifications
- Write the new terms and vocabulary on the board/overhead.
- ASA Congruence Postulate
- AAS Congruence Theorem
- Review the difference between a postulate and a theorem.
- Review the Third Angle Theorem
- Review two- column proofs
- Allow time for questions.
IV.AlternativeAssessment
- The best way to assess student learning in this lesson is through question and answer sessions.
- Be sure that you allow time for the students to participate in the lesson. Do not assume that they understand
the material. Verify that they do through their responses.
Proof Using SAS and HL
I.SectionObjectives
- Understand and apply the SAS Congruence Postulate.
- Identify the distinct characteristics and properties of right triangles.
- Understand and apply the HL Congruence Theorem.
- Understand that SSA does not necessarily prove triangles are congruent.
II.MultipleIntelligences
- Write these two points on the board/overhead. Write that students are going to know all of the theorems and
postulates that can prove congruence, and that they are going to understand all of the combinations of sides
and angles that do not prove congruence. - Use the uncooked spaghetti throughout this lesson with the protractors.
- As each exercise is described in the text, walk the students through using the uncooked spaghetti and the
protractors to test out each theorem. - Then use the uncooked spaghetti to show how the AAA does not prove congruence but similarity.
- Demonstrate this by creating two different size triangles that have the same angle measurements. Then the
students will see that although the angle measurements are the same, the triangles are not congruent. - Teach the Pythagorean Theorem. Connect this theorem with the HL Congruence Theorem.
- Make this lesson as interactive as possible by using the protractors and the uncooked spaghetti to model each
part of the lesson. - Intelligences- linguistic, logical- mathematical, bodily- kinesthetic, visual- spatial, interpersonal.
III.SpecialNeeds/Modifications
Chapter 4. Geometry TE - Differentiated Instruction