Subjects

Knowunity AI

Creator Program

Open the App

Subjects

GeometryGeometry816 views·Updated Jul 23, 2026·2 pages

Proportionality and Similarity Theorems for Triangles: Proof, PDF, Formula, Calculator

The triangle proportionality theoremand similarity concepts form fundamental principles...

1
of 2
6.5 and 6.6 Proportionality  – page 1

Page 2: Advanced Proportionality and Similarity Transformations

This page covers additional theorems about proportionality and introduces similarity transformations through dilations. It explains how parallel lines interact with transversals and how angle bisectors create proportional segments.

Definition: A dilation is a transformation that creates a similar figure by multiplying all distances from a center point by a scale factor k.

Example: When dilating point (x,y) with respect to the origin, the new coordinates become (kx, ky), where k is the scale factor.

Highlight: For dilations, if 0 < k < 1, the result is a reduction, while k > 1 produces an enlargement.

Vocabulary: A transversal is a line that intersects two or more other lines, while parallel lines are lines that never intersect.

Quote: "If three parallel lines intersect two transversals, then they divide the transversals proportionally."

2
of 2
6.5 and 6.6 Proportionality  – page 2

Page 1: Fundamental Triangle Similarity Theorems

This page introduces three crucial theorems related to triangle similarity and proportionality. The SAS similarity theorem establishes that two triangles are similar when they share a congruent angle and the sides including that angle are proportional.

Definition: The triangle proportionality theorem states that when a line parallel to one side of a triangle intersects the other two sides, it divides those sides proportionally.

Example: If line segment RT is parallel to side QS in triangle PQS, then PR/PQ = RT/QS.

Highlight: The converse of the triangle proportionality theorem proves that if a line divides two sides of a triangle proportionally, then it must be parallel to the third side.

Vocabulary: Congruent angles are angles that have the same measure, while proportional sides maintain equal ratios.

We thought you’d never ask...

Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.

You can download the app in the Google Play Store and in the Apple App Store.

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

Most popular content: Sas (side-angle-side) Similarity Theorem

1

Most popular content in Geometry

9

Most popular content

9
I
SAT®SAT®

Introduction to SAT Error Pattern Analysis

Practice identifying common reasoning traps and misinterpretations in SAT reading and math stimuli to understand why distractors are plausible.

9th2,1840
C
BiologyBiology

Cell Organelles

This Quiz Is To Test Your Knowledge Of Cell Organelles And Their Functions Inside The Cell. It Can Also Be A Study Guide To Remember Them Better.

6th6930
F
AP PsychologyAP Psychology

Foundations of Ethical Guidelines in Research

Practice the core principles of the APA ethical code including informed consent, debriefing, and the role of Institutional Review Boards.

9th1,3370
B
BiologyBiology

biology cell organelles and functions

Do you know the cell organelles and their functions?

9th4800
I
SAT®SAT®

Introduction to SAT Scoring and Scaled Results

Practice interpreting how raw scores are converted to the 1600-point scale and identifying the composition of section scores.

9th8520
F
AP PsychologyAP Psychology

Foundations of Research Design and Methodology

Practice distinguishing between different research methods including experiments, correlations, and case studies while identifying key variables.

9th6670
M
MathematicsMathematics

Math Made Easy: Essential Concepts for Grade 7

Master key math concepts with this comprehensive flashcard set designed specifically for 7th graders. Boost your understanding and ace your exams!

7th7561
M
BiologyBiology

Mitosis and Cell Division Flashcards

These flashcards cover the basics of mitosis and why cell division occurs in the first place.

9th3460
H
AP PsychologyAP Psychology

Historical Foundations of Psychology

Practice distinguishing between structuralism, functionalism, and the early philosophical roots of psychological science.

9th1,0940

Students love us — and so will you.

4.6/5App Store
4.7/5Google Play

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan SiOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha KlichAndroid user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

AnnaiOS user

GeometryGeometry816 views·Updated Jul 23, 2026·2 pages

Proportionality and Similarity Theorems for Triangles: Proof, PDF, Formula, Calculator

The triangle proportionality theorem and similarity concepts form fundamental principles in geometry, explaining relationships between parallel lines, triangles, and their proportional segments. These theorems provide essential tools for solving geometric problems involving similar triangles and proportional relationships.

Key points:

  • The ...
1
of 2
6.5 and 6.6 Proportionality  – page 1

Sign up to see the content. It's free!

  • Access to all documents
  • Improve your grades
  • Join milions of students

Page 2: Advanced Proportionality and Similarity Transformations

This page covers additional theorems about proportionality and introduces similarity transformations through dilations. It explains how parallel lines interact with transversals and how angle bisectors create proportional segments.

Definition: A dilation is a transformation that creates a similar figure by multiplying all distances from a center point by a scale factor k.

Example: When dilating point (x,y) with respect to the origin, the new coordinates become (kx, ky), where k is the scale factor.

Highlight: For dilations, if 0 < k < 1, the result is a reduction, while k > 1 produces an enlargement.

Vocabulary: A transversal is a line that intersects two or more other lines, while parallel lines are lines that never intersect.

Quote: "If three parallel lines intersect two transversals, then they divide the transversals proportionally."

2
of 2
6.5 and 6.6 Proportionality  – page 2

Sign up to see the content. It's free!

  • Access to all documents
  • Improve your grades
  • Join milions of students

Page 1: Fundamental Triangle Similarity Theorems

This page introduces three crucial theorems related to triangle similarity and proportionality. The SAS similarity theorem establishes that two triangles are similar when they share a congruent angle and the sides including that angle are proportional.

Definition: The triangle proportionality theorem states that when a line parallel to one side of a triangle intersects the other two sides, it divides those sides proportionally.

Example: If line segment RT is parallel to side QS in triangle PQS, then PR/PQ = RT/QS.

Highlight: The converse of the triangle proportionality theorem proves that if a line divides two sides of a triangle proportionally, then it must be parallel to the third side.

Vocabulary: Congruent angles are angles that have the same measure, while proportional sides maintain equal ratios.

We thought you’d never ask...

Our AI companion is specifically built for the needs of students. Based on the millions of content pieces we have on the platform we can provide truly meaningful and relevant answers to students. But its not only about answers, the companion is even more about guiding students through their daily learning challenges, with personalised study plans, quizzes or content pieces in the chat and 100% personalisation based on the students skills and developments.

You can download the app in the Google Play Store and in the Apple App Store.

That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.

Most popular content: Sas (side-angle-side) Similarity Theorem

1

Most popular content in Geometry

9

Most popular content

9
I
SAT®SAT®

Introduction to SAT Error Pattern Analysis

Practice identifying common reasoning traps and misinterpretations in SAT reading and math stimuli to understand why distractors are plausible.

9th2,1840
C
BiologyBiology

Cell Organelles

This Quiz Is To Test Your Knowledge Of Cell Organelles And Their Functions Inside The Cell. It Can Also Be A Study Guide To Remember Them Better.

6th6930
F
AP PsychologyAP Psychology

Foundations of Ethical Guidelines in Research

Practice the core principles of the APA ethical code including informed consent, debriefing, and the role of Institutional Review Boards.

9th1,3370
B
BiologyBiology

biology cell organelles and functions

Do you know the cell organelles and their functions?

9th4800
I
SAT®SAT®

Introduction to SAT Scoring and Scaled Results

Practice interpreting how raw scores are converted to the 1600-point scale and identifying the composition of section scores.

9th8520
F
AP PsychologyAP Psychology

Foundations of Research Design and Methodology

Practice distinguishing between different research methods including experiments, correlations, and case studies while identifying key variables.

9th6670
M
MathematicsMathematics

Math Made Easy: Essential Concepts for Grade 7

Master key math concepts with this comprehensive flashcard set designed specifically for 7th graders. Boost your understanding and ace your exams!

7th7561
M
BiologyBiology

Mitosis and Cell Division Flashcards

These flashcards cover the basics of mitosis and why cell division occurs in the first place.

9th3460
H
AP PsychologyAP Psychology

Historical Foundations of Psychology

Practice distinguishing between structuralism, functionalism, and the early philosophical roots of psychological science.

9th1,0940

Students love us — and so will you.

4.6/5App Store
4.7/5Google Play

The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.

Stefan SiOS user

This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.

Samantha KlichAndroid user

Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.

AnnaiOS user