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# Triangle Proportionality

## Sides divided by a line parallel to the third side of a triangle.

Levels are CK-12's student achievement levels.
Basic Students matched to this level have a partial mastery of prerequisite knowledge and skills fundamental for proficient work.
At Grade (Proficient) Students matched to this level have demonstrated competency over challenging subject matter, including subject matter knowledge, application of such knowledge to real-world situations, and analytical skills appropriate to subject matter.
Advanced Students matched to this level are ready for material that requires superior performance and mastery.

## Triangle Proportionality

This concept teaches students how to determine if lines in triangles are parallel and find missing lengths using the Triangle Proportionality Theorem.
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• Video

## Triangle Proportionality Principles

This video gives more detail about the mathematical principles presented in Triangle Proportionality.
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## Triangle Proportionality Examples

This video shows how to work step-by-step through one or more of the examples in Triangle Proportionality.
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• Critical Thinking

## Triangle Proportionality Discussion Questions

A list of student-submitted discussion questions for Triangle Proportionality.
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• Real World Application

## Triangle Proportionality

How does NASA use proportionality to test space crafts?
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• Study Guide

## Proportionality Relationships Study Guide

This study guide looks at proportionality theorems for triangles and parallel lines intersected by transversals.
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