Home
Math by Grades Pre-K
Kindergarten
Grade 1
Grade 2
Grade 3
Grade 4
Grade 5
Grade 6
Grades 7 and 8
Grades 9 and 10
Grades 11 and 12
Math by Topics Arithmetic
Algebra
Geometry Help
Math Word Problems
Trigonometry
Statistics
Probability
PreCalculus
Calculus
Set Theory
Matrices
Vectors
Math Worksheets Math Worksheets
_interactive
Math for Specific Tests SAT Math
ACT Math
GMAT Math
GRE Math
High School, Regents
California Standards
GCSE Maths
A Level Maths
Math Fun and Games Math Trivia
Math Games
Fun Games
Mousehunt Guide
Exam Preparation SAT Preparation
ACT Preparation
GRE Preparation
GMAT Preparation
Math in Video Lessons Basic Algebra
Intermediate Algebra
College Algebra
High School Geometry
College Calculus
Linear Algebra
Engineering Math
Singapore Math
Science Biology
Chemistry
Science Projects
High School Biology
High School Chemistry
High School Physics
GCSE Biology
Others English Help
ESL, IELTS, TOEFL
Programming
Animal Facts
Tutoring Services
What's New

 

Proving Triangles are Similar

Videos, worksheets, stories and songs to help Grade 8 students learn how to determine if two triangles are similar.

 

 

Similar Triangle Proofs
Students learn that if two angles of one triangle are congruent to two angles of another triangle, then the triangles are similar (Angle-Angle Similarity Postulate, or AA Similarity Postulate). Students also learn that the scale factor is ratio of the lengths of two corresponding sides. Students are then asked to use these concepts to determine whether given triangles are similar, and to find the missing side lengths in similar triangles.

 

 

Proving Triangles are Similar
Students learn the following theorems related to similar triangles.

 

 

Similar Triangles in Circles and Right Triangles
Two triangles in a circle are similar if two pairs of angles have the same intercepted arc. Sharing an intercepted arc means the inscribed angles are congruent. Since these angles are congruent, the triangles are similar by the AA shortcut. If an altitude is drawn from the right angle in a right triangle, three similar triangles are formed, also because of the AA shortcut.

 

 

 

Custom Search

 

We welcome your feedback, comments and questions about this site - please submit your feedback via our Feedback page.

 

© Copyright 2005, 2011 - onlinemathlearning.com
Embedded content, if any, are copyrights of their respective owners.


 

 

 

Custom Search