# Ch 28: FTCE Middle Grades Math: Similar & Congruent Triangle Proofs

### About This Chapter

### FTCE Middle Grades Math: Similar & Congruent Triangle Proofs - Chapter Summary

The FTCE Middle Grades Math test will include questions that test your knowledge of triangle proofs. You can prepare to successfully answer these questions by using this chapter to go over:

- Theorems related to triangles
- Similar triangles
- Triangle congruence postulates
- The transitive property
- Similarity transformations
- Properties of concurrent lines

Build your confidence by using your knowledge of these proofs to complete the quizzes that accompany each lesson. Use the chapter test to make sure you can put all of these mathematical concepts together.

### 1. Triangle Proportionality Theorem

Watch this video lesson to learn all about the triangle proportionality theorem and how you can use this interesting theorem to help you solve problems. Learn how a parallel line can create sides that are proportional to each other.

### 2. How to Identify Similar Triangles

Similar triangles have the same characteristics as similar figures but can be identified much more easily. Learn the shortcuts for identifying similar triangles here and test your ability with a quiz.

### 3. Applications of Similar Triangles

Similar triangles are used to solve problems in everyday situations. Learn how to solve with similar triangles here, and then test your understanding with a quiz.

### 4. Triangle Congruence Postulates: SAS, ASA & SSS

When we have two triangles, how can we tell if they're congruent? They may look the same, but you can be certain by using one of several triangle congruence postulates, such as SSS, SAS or ASA.

### 5. The AAS (Angle-Angle-Side) Theorem: Proof and Examples

When trying to find out if triangles are congruent, it's helpful to have as many tools as possible. In this lesson, we'll add to our congruence toolbox by learning about the AAS theorem, or angle-angle-side.

### 6. Perpendicular Bisector Theorem: Proof and Example

Perpendicular bisectors are multifunctional lines. They're not only perpendicular to the line in question, they also neatly divide it into two equal halves. In this lesson, we'll learn about the perpendicular bisector theorem.

### 7. Angle Bisector Theorem: Proof and Example

The angle bisector theorem sounds almost too good to be true. In this lesson, we set out to prove the theorem and then look at a few examples of how it's used.

### 8. The Transitive Property of Similar Triangles

Watch this video lesson and you will understand what the transitive property is and how it applies to similar triangles. Watch as we apply the transitive property to three similar triangles.

### 9. Congruency of Isosceles Triangles: Proving the Theorem

Isosceles triangles have two equal sides. Are the base angles also equal? In this lesson, we'll prove how this is true. We'll also prove the theorem's converse.

### 10. Similarity Transformations in Corresponding Figures

Watch this video lesson to learn how you can tell if two figures are similar by using similarity transformations. Learn how to find the corresponding sides and angles and then how to compare them.

### 11. Properties of Concurrent Lines in a Triangle

Centroids, orthocenters, incenters, circumcenters, oh my! Don't worry though. In this lesson, we master the various terms for concurrent lines in triangles and match them to altitudes, angle bisectors, perpendicular bisectors and medians.

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### Other Chapters

Other chapters within the FTCE Middle Grades Mathematics 5-9 (025): Practice & Study Guide course

- About the FTCE Middle Grades Mathematics Test
- FTCE Middle Grades Math: Mathematical Reasoning
- FTCE Middle Grades Math: Problem-Solving Strategies
- FTCE Middle Grades Math: The Real Number System
- FTCE Middle Grades Math: Fractions, Decimals & Percents
- FTCE Middle Grades Math: Ratios & Proportions
- FTCE Middle Grades Math: Factoring
- FTCE Middle Grades Math: Solving Word Problems
- FTCE Middle Grades Math: Exponents & Exponential Expressions
- FTCE Middle Grades Math: Basic Algebraic Expressions
- FTCE Middle Grades Math: Distributing in Algebra
- FTCE Middle Grades Math: Rational Expressions
- FTCE Middle Grades Math: Square Roots
- FTCE Middle Grades Math: Radical Expressions
- FTCE Middle Grades Math: Linear Equations
- FTCE Middle Grades Math: Systems of Linear Equations
- FTCE Middle Grades Math: Solving & Graphing Inequalities
- FTCE Middle Grades Math: Introduction to Functions
- FTCE Middle Grades Math: Graphing Functions
- FTCE Middle Grades Math: Quadratic Functions
- FTCE Middle Grades Math: Polynomial Functions
- FTCE Middle Grades Math: Summarizing Data
- FTCE Middle Grades Math: Charting Data
- FTCE Middle Grades Math: Sampling
- FTCE Middle Grades Math: Probability Distributions
- FTCE Middle Grades Math: Lines & Angles
- FTCE Middle Grades Math: Properties of Triangles
- FTCE Middle Grades Math: Right Triangle Proofs
- FTCE Middle Grades Math: Quadrilaterals & Polygons
- FTCE Middle Grades Math: Area & Perimeter
- FTCE Middle Grades Math: Circles & Arc of a Circle
- FTCE Middle Grades Math: Coordinate Geometry
- FTCE Middle Grades Math: Transformations in Geometry
- FTCE Middle Grades Math: Principles of Measurement
- FTCE Middle Grades Math: Surface Area & Volume
- FTCE Middle Grades Math: Connecting Math Concepts
- FTCE Middle Grades Math: Instructional Strategies & Tools
- FTCE Middle Grades Math: Assessing Student Learning
- FTCE Middle Grades Mathematics 5-9 Flashcards