# Ch 42: OAE Middle Grades Math: Triangle Theorems & Proofs

### About This Chapter

## OAE Middle Grades Math: Triangle Theorems & Proofs - Chapter Summary

Watch entertaining video lessons to get the refresher you need as you prepare to take the OAE Middle Grades Mathematics test. You'll brush up on triangle theorems and proofs so you're ready to answer questions related to the following on the exam:

- Understanding applications of similar triangles
- Examining triangle congruence postulates, congruence proofs and the converse of a statement
- Analyzing similarity transformations in corresponding figures
- Using congruence and similarity to prove relationships in figures
- Proving the angle-angle side, hypotenuse angle and hypotenuse leg
- Examining perpendicular and angle bisector theorem

Instructors in the video lessons provide an in-depth look at triangle theorems and proofs to ensure you're prepared to tackle them on the exam. The materials are also entertaining to watch, which makes comprehending the materials easy and fun.

### OAE Middle Grades Math: Triangle Theorems & Proofs Chapter Objectives

The OAE Middle Grades Mathematics test is designed to gauge your knowledge and skills of the subject to ensure you're prepared to teach it in the classroom and are qualified to acquire a subject-specific educator license in Ohio. This OAE Middle Grades Math: Triangle Theorems & Proofs offers topics covered in the measurement and geometry portion of the exam, which constitutes 25% of the test. By watching the engaging video lessons in this chapter, you can refresh your knowledge of triangle theorems and proofs to ensure you're prepared to tackle this section of the test. You can also use self-assessment quizzes to practice answering questions similar to those you'll see on test day.

The assessment is composed of all multiple-choice questions, some of which are accompanied by a graph, diagram or illustration to help you solve the problem. Each question is followed by four answers, one of which you will be asked to choose as the best response.

### 1. 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.

### 2. 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.

### 3. Congruence Proofs: Corresponding Parts of Congruent Triangles

Congruent triangles have congruent sides and angles, and the sides and angles of one triangle correspond to their twins in the other. In this lesson, we'll try practice with some geometric proofs based around this theorem.

### 4. Converse of a Statement: Explanation and Example

Just because a conditional statement is true, is the converse of the statement always going to be true? In this lesson, we'll learn the truth about the converse of statements.

### 5. 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.

### 6. Practice Proving Relationships using Congruence & Similarity

In geometry, if two shapes are similar they have the same shape but different sizes, while two congruent shapes have the same shape and size. In this lesson, you will learn how to prove that shapes are similar or congruent.

### 7. 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.

### 8. The HA (Hypotenuse Angle) Theorem: Proof, Explanation, & Examples

In this lesson, we'll learn about the hypotenuse angle theorem. With this theorem, we can prove two right triangles are congruent with just congruent hypotenuses and acute angles.

### 9. The HL (Hypotenuse Leg) Theorem: Definition, Proof, & Examples

In this lesson, we'll learn about the hypotenuse leg theorem. This theorem enables us to prove two right triangles are congruent based on just two sides.

### 10. 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.

### 11. 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.

### 12. Congruency of Right Triangles: Definition of LA and LL Theorems

In this lesson, we'll learn two theorems that help us prove when two right triangles are congruent to one another. The LA theorem, or leg-acute, and LL theorem, or leg-leg, are useful shortcuts for proving congruence.

### 13. 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.

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### Other Chapters

Other chapters within the Ohio Assessments for Educators - Middle Grades Mathematics (030): Practice & Study Guide course

- OAE Middle Grades Math: Basic Arithmetic Operations
- OAE Middle Grades Math: Solving Math Word Problems
- OAE Middle Grades Math: Properties of Numbers
- OAE Middle Grades Math: Roots & Radical Expressions
- OAE Middle Grades Math: Exponents & Exponential Expressions
- OAE Middle Grades Math: Scientific Notation
- OAE Middle Grades Math: Simplifying Whole Number Expressions
- OAE Middle Grades Math: Integers
- OAE Middle Grades Math: Rational Numbers
- OAE Middle Grades Math: Estimating & Rounding
- OAE Middle Grades Math: Number Theory
- OAE Middle Grades Math: Introduction to Fractions
- OAE Middle Grades Math: Operations with Fractions
- OAE Middle Grades Math: Introduction to Decimals
- OAE Middle Grades Math: Operations with Decimals
- OAE Middle Grades Math: Percents
- OAE Middle Grades Math: Rates, Ratios & Proportions
- OAE Middle Grades Math: Money & Consumer Math
- OAE Middle Grades Math: Factoring
- OAE Middle Grades Math: Properties of Functions
- OAE Middle Grades Math: Graphing Functions
- OAE Middle Grades Math: Monomials & Polynomials
- OAE Middle Grades Math: Writing Algebraic Expressions
- OAE Middle Grades Math: Basic Algebraic Expressions
- OAE Middle Grades Math: Algebraic Distribution
- OAE Middle Grades Math: Writing & Solving One-Step Equations
- OAE Middle Grades Math: Writing & Solving Two-Step Equations
- OAE Middle Grades Math: Simplifying & Solving Rational Expressions
- OAE Middle Grades Math: The Coordinate Graph
- OAE Middle Grades Math: Linear Equations
- OAE Middle Grades Math: Systems of Linear Equations
- OAE Middle Grades Math: Negative Numbers
- OAE Middle Grades Math: Absolute Value
- OAE Middle Grades Math: Inequalities
- OAE Middle Grades Math: Number Patterns & Sequences
- OAE Middle Grades Math: Measurement
- OAE Middle Grades Math: Perimeter & Area
- OAE Middle Grades Math: Polyhedrons & Geometric Solids
- OAE Middle Grades Math: Symmetry, Similarity & Congruence
- OAE Middle Grades Math: Properties of Lines
- OAE Middle Grades Math: Triangles
- OAE Middle Grades Math: Similar Polygons
- OAE Middle Grades Math: The Pythagorean Theorem
- OAE Middle Grades Math: Quadrilaterals
- OAE Middle Grades Math: Circles
- OAE Middle Grades Math: Circular Arcs & Measurement
- OAE Middle Grades Math: Transformations
- OAE Middle Grades Math: Data & Graphs
- OAE Middle Grades Math: Sets
- OAE Middle Grades Math: Statistics
- OAE Middle Grades Math: Data Collection
- OAE Middle Grades Math: Samples & Populations
- OAE Middle Grades Math: Probability