Geometry, Teacher\'s Edition

(Axel Boer) #1

  • Students will apply the HL Congruence Theorem.


IV.NotesonAssessment



  • Check student diagrams.

  • Is the work accurately labeled with measurements?

  • Did the students make note of the two triangles?

  • Which postulate or theorem did the student use to prove congruency?

  • Is the student aware of the properties of right triangles?

  • Are the right triangles noted in the student’s work?


Using Congruent Triangles


I.SectionObjectives



  • Apply various triangles congruence postulates and theorems.

  • Know the ways in which you can prove parts of a triangle congruent.

  • Find distances using Congruent Triangles.

  • Use construction techniques to create Congruent Triangles.


II.ProblemSolvingActivity-TheKiteDesign



  • Students will need chart paper, compasses, rulers and colored pencils.

  • Here is the problem.

  • “Jonas is working on designing a kite. He knows that for his kite to fly well, that it needs to be created with
    four Congruent Triangles. Jonas starts by drawing a line segment that will serve as the center line of his kite.
    Now he needs to draw in the four triangles. He can’t remember how to do it.

  • Your task is to use a compass and a straightedge to help Jonas design his kite.

  • Remember to measure your work so that it is accurate.

  • Here is the line segment that Jonas started with.

  • Figure04.06.01

  • Allow time for the students to work.

  • When finished, the students can decorate their kites.


III.MeetingObjectives



  • Students will apply various triangle congruence postulates and theorems.

  • Students will use construction techniques to create Congruent Triangles.

  • Students will show their work in a design.


IV.NotesonAssessment



  • Leave students alone to work on this problem.

  • If students are having trouble, refer them back to the text to follow the steps for the construction.

  • Assess student work for accuracy and creativity.

  • Provide feedback/correction when students are finished.

  • Create a class display with the designs.


5.4. Congruent Triangles

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