ALEX Classroom Resource

  

Geometry Module 2, Topic D: Applying Similarity to Right Triangles

  Classroom Resource Information  

Title:

Geometry Module 2, Topic D: Applying Similarity to Right Triangles

URL:

https://www.engageny.org/resource/geometry-module-2-topic-d-overview

Content Source:

EngageNY
Type: Lesson/Unit Plan

Overview:

In Module 2, Topic D, students use their understanding of similarity and focus on right triangles as a lead-up to trigonometry. In Lesson 21, students use the AA criterion to show how an altitude drawn from the vertex of the right angle of a right triangle to the hypotenuse creates two right triangles similar to the original right triangle. Students examine how the ratios within the three similar right triangles can be used to find unknown side lengths. Work with lengths in right triangles lends itself to expressions with radicals. In Lessons 22 and 23, students learn to rationalize fractions with radical expressions in the denominator and also to simplify, add, and subtract radical expressions. In the final lesson of Topic D, students use the relationships created by an altitude to the hypotenuse of a right triangle to prove the Pythagorean theorem.

Content Standard(s):
Mathematics
MA2015 (2016)
Grade: 9-12
Geometry
17 ) Prove theorems about triangles. Theorems include a line parallel to one side of a triangle divides the other two proportionally, and conversely; and the Pythagorean Theorem proved using triangle similarity. [G-SRT4]

Tags: Pythagorean Theorem, similarity, theorem, triangles
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Comments

There are four lessons in this topic.

This resource is free for teachers to access and use. All resources required for the lessons are available to print from the site. 

  This resource provided by:  
Author: Hannah Bradley