- (Sides) Theorem- walk through the proof step by step. Provide students with a brief explanation of each step.
- Review briefly each previously learned term as it is introduced. Example- ruler postulate, angle addition,
substitution - (Angle) Theorem- on board
- Review what is meant by indirect reasoning- by assumption or conjecture
- Define corollary
IV.AlternativeAssessment
- Collect student work on with the triangles on the coordinate grid.
- Use these diagrams and the inequality statements to assess student understanding.
- You can use this as a classwork grade.
- It is also useful to assess the students that are in need of assistance.
Inequalities in Two Triangles
I.SectionObjectives
- Determine relationships among the angles and sides of two triangles.
- Apply the SAS and SSS Triangle Inequality Theorems to solve problems.
- Multiple Intelligences
- Expand this lesson by creating a model for students to use throughout the lesson.
- Before beginning, have students use three long strips of paper. Put fasteners to connect the strips of paper into
a long strip. - The fasteners will be moveable so that the students can manipulate the pieces into different shaped triangles.
This is how they can demonstrate proving each of the theorems in the lesson. - Have each student work with a partner since we will be working with two triangles.
- After going through the first example on SAS Inequality Theorem, have students work in pairs to test it out
themselves. - Offer time for feedback.
- Then go through the other examples in the lesson, after each example, have students work to test out the
theorems with their model. - Offer time for feedback.
- Intelligences- linguistic, logical- mathematical, visual- spatial, bodily- kinesthetic, interpersonal, intraper-
sonal.
III.SpecialNeeds/Modifications
- Review inequalities in one triangle first.
- Review congruent triangles.
- Write all of the theorems on the board/overhead.
- Request that students copy these notes into their notebooks.
- Allow time for questions.
IV.AlternativeAssessment
- Assess student understanding through observation of the partner work.
- Interact with students as they work through proving each theorem.
- Listen to student feedback and correct any unclear information.
4.5. Relationships Within Triangles