Triangle similarity
content
Abstract
Triangle similarity & the trigonometric ratios is the fundamental to trigonometry. This lesson is developed with CCRS G.SRT.5 Geometry: Similarity, Right Triangles.
Learner Audience / Primary Users
Students newly get to know trigonometry.
Educational Use
Curriculum / Instruction
Informal Education
College & Career Readiness Standards (CCRS) Alignment
Level: Adult Education
Grade Level: E, (G.SRT.5)
Subject: Mathematics
Domain or Strand:
Domain:
trigonometry
Standard Description:
Use congruence and similarity criteria for triangles to solve problems and to prove relationships in geometric figures.
Language
English
Material Type
Instructional Material
Khan Academy
Other OER
Learning Goals
The purpose of this lesson is for learners to be able to:
Use congruence and similarity criteria for triangles to solve problems and to prove relationships in geometric figures.
Keywords
Designers for Learning
Adult Education
Trigonometry
Time Required for Lesson
30 minutes
Prior Knowledge
No
Required Resources
A computer with Internet access
Lesson Author & License
Lesson Author: Rongsheng Wang
License: Creative Commons License; Creative Commons CC BY 4.0 license
Instructional Strategies and Activities
Warm-Up
Time: 2 minutes
Show students with some right triangles, as well as some triangles with similarity.
Introduction
Time: 3 minutes
Introduce the definition and concepts of Triangle similarity & the trigonometric ratios.
Presentation / Modeling / Demonstration
Time: 10 minutes
PowerPoint presentation to students with key terms, and play the Khan Academy video clip to them.
Guided Practice
Time: 5 minutes
Lead the students to distinct whether two given triangles are similarity.
Evaluation
Time: 5 minutes
Give students a few sets of triangles, and ask them to distinct whether any of them are similarity.
Application
Time: 5 minutes
Lead students to brainstorm how similarities can be used in daily life, e.g. modelling,architectural design, etc.