How Do You Use the Triangle Proportionality Theorem to Find Missing Lengths in a Diagram?

How Do You Use the Triangle Proportionality Theorem to Find Missing Lengths in a Diagram?

Note:

This tutorial shows you how the Triangle Proportionality Theorem can be used to find a missing length in a diagram. Take a look!

Keywords:

  • problem
  • triangle
  • proportionality
  • side-splitter
  • missing-side

Background Tutorials

  • Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.

      • What are Parallel Lines?What are Parallel Lines?

      What are Parallel Lines?

      Lines that are parallel have a very special quality. Without this quality, these lines are not parallel. In this tutorial, take a look at parallel lines and see how they are different from any other kind of lines!

  • Decide whether two quantities are in a proportional relationship, e.g., by testing for equivalent ratios in a table or graphing on a coordinate plane and observing whether the graph is a straight line through the origin.

      • What's a Proportion?What's a Proportion?

      What's a Proportion?

      The idea of proportions is that a ratio can be written in many ways and still be equal to the same value. That's why proportions are actually equations with equal ratios. This is a bit of a tricky definition, so make sure to watch the tutorial!

  • Use proportional relationships to solve multistep ratio and percent problems.

      • How Do You Solve a Proportion Using Cross Products?How Do You Solve a Proportion Using Cross Products?

      How Do You Solve a Proportion Using Cross Products?

      Want to solve a percent proportion? Just use the means extremes property of proportions to cross multiply! Solve for the variable, and you have your answer! Learn how with this tutorial.

      • What's the Means-Extremes Property of Proportions?What's the Means-Extremes Property of Proportions?

      What's the Means-Extremes Property of Proportions?

      The means-extremes property of proportions allows you to cross multiply, taking the product of the means and setting them equal to the product of the extremes. This property comes in handy when you're trying to solve a proportion. Watch this tutorial to learn more!

      • What are the Means and Extremes of Proportions?What are the Means and Extremes of Proportions?

      What are the Means and Extremes of Proportions?

      A proportion is just an equation where two ratios are equal, and each piece of the proportion has a special name. This tutorial will teach you those names, and this will help you understand cross multiplication when you learn it later!

  • Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles.

      • What is a Triangle?What is a Triangle?

      What is a Triangle?

      You can't learn everything about math without dealing with triangles. Did you know that there are different types of triangles? Check out this tutorial, and learn about triangles and their different types!