Similar Triangle Proportionality

 This is one lesson in a larger Unit Plan that introduces triangular relationships through the lens of building a treehouse with a variety of triangular characteristics.  It has proofs, real world problems, constructions, a unit project, assessments, and more. Lesson 17, “Proportional Parts of Similar Triangles?", involves the topics of triangle similarity, geometric mean, perpendicular bisectors, altitudes and angle bisectors.  It includes and investigation which can be done with Sketchpad or by hand.  The entire unit plan can be found hereThis lesson plan has an investigation into the proportional parts of triangles. Sketchpad can be used or ruler, compass, and protractor. There are also practice worksheets and a series of real world problems. Grouping is suggested for part of the problems. The teacher section suggests numerous visual sources including a powerpoint.

Standards & Objectives

Essential and guiding questions: 
  • How are the theorems in this lesson connected?
  • Which of these theorems would appear to most useful in the real world?

Lesson Variations

Blooms taxonomy level: 
Understanding

Helpful Hints

Materials:

  • Computer with internet capabilities

References

Contributors: