# Ch 31: 8th Grade Math: Triangles in Geometry

### About This Chapter

## 8th Grade Math: Triangles in Geometry - Chapter Summary

Do you want your students to understand triangles? The clever and short video lessons in this chapter strive to engage students while teaching them triangle parts, types, constructions, and techniques in ways they won't forget. You can determine your students' understanding by using multiple-choice quizzes and a chapter exam at the end of the lesson.

## Chapter Lessons and Objectives

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

Triangles: Definition and Properties | Students learn vocabulary terms related to triangles like adjacent, vertex, vertices, side, opposite, base, apex, and height. |

Classifying Triangles by Angles and Sides | With this lesson, students use the angles and sides of triangles to determine the triangle type. |

Interior and Exterior Angles of Triangles: Definition and Examples | Instructors explain how to identify the interior and exterior angles of triangles. |

How to Identify Similar Triangles | Students learn ways to identify similar triangles. |

Angles and Triangles: Practice Problems | Students have the chance to practice solving for angles and triangles. |

Constructing the Median of a Triangle | Chapter leads students through the steps of constructing the median of a triangle. |

Median, Altitude, and Angle Bisectors of a Triangle | Students learn the meanings of median, altitude, and angle bisectors and ways to identify them in a triangle. |

Constructing Triangles: Types of Geometric Construction | In this lesson, students learn to construct triangles using different combinations of given sides and angles. |

Properties of Concurrent Lines in a Triangle | Students examine some properties of concurrent lines in a triangle, such as centroid, altitude, angle bisector, incenter, and orthocenter. |

### 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. Constructing the Median of a Triangle

If you have one triangle and want to divide it, you can use a median line. Medians have special geometric properties that we'll learn about in this lesson.

### 7. Median, Altitude, and Angle Bisectors of a Triangle

Line segments in triangles are just clutter; they have special names and qualities depending on how they're drawn. In this lesson, we'll learn about medians, altitudes and angle bisectors.

### 8. Constructing Triangles: Types of Geometric Construction

When you're asked to construct a triangle, it's time to break out that compass and straight edge! In this lesson, find out how to construct triangles no matter what you're given.

### 9. 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 8th Grade Math: Practice & Review course

- 8th Grade Math: Basic Arithmetic Operations
- 8th Grade Math: Divisibility
- 8th Grade Math: Number Properties
- 8th Grade Math: Number Theory
- 8th Grade Math: Factoring
- 8th Grade Math: Estimation and Rounding
- 8th Grade Math: Whole Numbers
- 8th Grade Math: Simplifying Whole Number Expressions
- 8th Grade Math: Negative Numbers
- 8th Grade Math: Absolute Value
- 8th Grade Math: Integers
- 8th Grade Math: Rational Numbers
- 8th Grade Math: Inequalities
- 8th Grade Math: Introduction to Decimals
- 8th Grade Math: Operations with Decimals
- 8th Grade Math: Introduction to Fractions
- 8th Grade Math: Operations with Fractions
- 8th Grade Math: Percents
- 8th Grade Math: Exponents & Exponential Expressions
- 8th Grade Math: Roots & Radical Expressions
- 8th Grade Math: Basic Algebraic Expressions
- 8th Grade Math: Algebraic Distribution
- 8th Grade Math: Simplifying & Solving Rational Expressions
- 8th Grade Math: The Coordinate Graph
- 8th Grade Math: Linear Equations
- 8th Grade Math: Systems of Linear Equations
- 8th Grade Math: Properties of Functions
- 8th Grade Math: Graphing Functions
- 8th Grade Math: Solving Math Word Problems
- 8th Grade Math: Introduction to Geometric Figures
- 8th Grade Math: Quadrilaterals in Geometry
- 8th Grade Math: Circles in Geometry
- 8th Grade Math: Circular Arcs & Measurement in Geometry
- 8th Grade Math: Polyhedrons and Geometric Solids
- 8th Grade Math: Symmetry, Similarity & Congruence in Geometry
- 8th Grade Math: Triangle Theorems and Proofs in Geometry
- 8th Grade Math: Similar Polygons in Geometry
- 8th Grade Math: The Pythagorean Theorem in Geometry
- 8th Grade Math: Units of Measurement
- 8th Grade Math: Measuring Perimeter & Area
- 8th Grade Math: Data & Graphs
- 8th Grade Math: Probability
- 8th Grade Math: Statistics
- 8th Grade Math: Rates, Ratios & Proportions
- 8th Grade Math: Consumer Math
- 8th Grade Math: Number Sequences
- 8th Grade Math: Sets & Subsets
- 8th Grade Math: Algebraic Monomials & Polynomials