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 here. This 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.
