# Ch 20: 3rd Grade Math: Triangles

### About This Chapter

## Triangles - Chapter Summary

The video lessons in the Triangles chapter illustrate the different components of triangles and the various types of triangles. They teach 3rd graders how to identify and classify these geometric shapes. The video lessons are often less than ten minutes long, and they include video tags for moving around between topics.

## Chapter Lessons and Objectives

Lesson | Objective |
---|---|

Triangles: Definition and Properties | Students learn about the vertex, base, height and apex of triangles. |

Classifying Triangles by Angles and Sides | Instructors teach 3rd graders about the different kinds of triangles that exist. |

Interior and Exterior Angles of Triangles | Teachers explain the angles of triangles in this lesson. |

How to Identify Similar Triangles | Students are taught how to recognize these shapes. |

Angles and Triangles: Practice Problems | Students are allowed to practice what they've learned. |

Practice Identifying Triangles | Instructors teach the differences between acute, obtuse, isosceles, equilateral and right triangles. |

### 1. Triangles: Definition and Properties

What makes a shape a triangle? In this lesson, we'll explore the definition of a triangle, then analyze the parts of triangles, including the vertices, base and height.

### 2. Classifying Triangles by Angles and Sides

Not all triangles are the same. There are equilateral, isosceles and scalene triangles. Then there are right, acute and obtuse triangles. In this lesson, we'll learn how to classify triangles using their sides and angles.

### 3. Interior and Exterior Angles of Triangles: Definition & Examples

Knowing just a few things about the interior or exterior angles of triangles is sometimes all you need to put all the pieces together. Find out more in this lesson.

### 4. 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.

### 5. Angles and Triangles: Practice Problems

Want more practice solving with angle pairs? How about more review for solving angles in triangles? Look no further. Get more practice here, and test your ability with a quiz.

### 6. Practice Identifying Triangles

After watching this video lesson, you will be able to identify all kinds of triangles. You'll learn the identifying factors of each type of triangle, including the kinds of angles and lines to look for.

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### Other Chapters

Other chapters within the 3rd Grade Math: Practice & Review course

- 3rd Grade Math: Number Sense & Arithmetic
- 3rd Grade Math: Number Properties
- 3rd Grade Math: Solving Math Word Problems
- 3rd Grade Math: Estimation & Rounding
- 3rd Grade Math: Addition
- 3rd Grade Math: Subtraction
- 3rd Grade Math: Multiplication
- 3rd Grade Math: Multiples of Whole Numbers
- 3rd Grade Math: Multiplication Skills Practice
- 3rd Grade Math: Division
- 3rd Grade Math: Division Skills Practice
- 3rd Grade Math: Simplifying Whole Number Expressions
- 3rd Grade Math: Basic Algebraic Expressions
- 3rd Grade Math: Writing Algebraic Expressions
- 3rd Grade Math: Data & Graphs
- 3rd Grade Math: Probability & Statistics
- 3rd Grade Math: Units of Measurement
- 3rd Grade Math: Introduction to Geometric Figures
- 3rd Grade Math: Angles
- 3rd Grade Math: Quadrilaterals
- 3rd Grade Math: Perimeter, Area & Volume
- 3rd Grade Math: Symmetry, Similarity & Congruence
- 3rd Grade Math: Fractions
- 3rd Grade Math: Decimals
- 3rd Grade Math: Money
- 3rd Grade Math: Time