# Ch 37: 6th-8th Grade Geometry: Triangles

### About This Chapter

## Triangles - Chapter Summary

This chapter's online video lessons explain the meanings of terms such as centroid, orthocenter, altitude, median and incenter. The lessons explore the language of similarity, and they teach your 6th-8th grade students to differentiate between scalene, acute, isosceles, equilateral and obtuse triangles. Assess your students' comprehension of geometric triangles by administering the quizzes and chapter examination.

## Chapter Lessons and Objectives

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

Triangles: Definition and Properties | This lesson teaches students about the various parts of triangles. |

Classifying Triangles by Angles and Sides | Students discover how to use a triangle's angles and sides to classify it. |

Interior and Exterior Angles of Triangles: Definition and Examples | This lesson explains the differences between interior and exterior angles. |

How to Identify Similar Triangles | Instructors describe the characteristics of similar triangles. |

Angles and Triangles: Practice Problems | Students learn the procedures for solving consecutive interior, corresponding, alternate exterior and alternate interior angles. |

Constructing the Median of a Triangle | Instructors demonstrate the use of the median line. |

Median, Altitude and Angle Bisectors of a Triangle | Students learn to identify the line segments of triangles. |

Constructing Triangles: Types of Geometric Construction | This lesson teaches students to use rulers or compasses to construct triangles. |

Properties of Concurrent Lines in a Triangle | Instructors teach students about the characteristics of concurrent lines. |

### 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 6th-8th Grade Math: Practice & Review course

- 6th-8th Grade Math: Basic Arithmetic Operations
- 6th-8th Grade Math: Divisibility
- 6th-8th Grade Math: Properties of Numbers
- 6th-8th Grade Math: Number Theory
- 6th-8th Grade Math: Factoring
- 6th-8th Grade Math: Estimating & Rounding
- 6th-8th Grade Math: Whole Numbers
- 6th-8th Grade Math: Simplifying Whole Number Expressions
- 6th-8th Grade Math: Negative Numbers
- 6th-8th Grade Math: Absolute Value
- 6th-8th Grade Math: Integers
- 6th-8th Grade Math: Rational Numbers
- 6th-8th Grade Math: Inequalities
- 6th-8th Grade Math: Introduction to Decimals
- 6th-8th Grade Math: Operations with Decimals
- 6th-8th Grade Math: Introduction to Fractions
- 6th-8th Grade Math: Operations with Fractions
- 6th-8th Grade Math: Percents
- 6th-8th Grade Math: Exponents & Exponential Expressions
- 6th-8th Grade Math: Roots & Radical Expressions
- 6th-8th Grade Algebra: Writing Algebraic Expressions
- 6th-8th Grade Algebra: Basic Algebraic Expressions
- 6th-8th Grade Algebra: Algebraic Distribution
- 6th-8th Grade Algebra: Writing & Solving One-Step Equations
- 6th-8th Grade Algebra: Writing & Solving Two-Step Equations
- 6th-8th Grade Algebra: Simplifying & Solving Rational Expressions
- 6th-8th Grade Math: The Coordinate Graph
- 6th-8th Grade Algebra: Linear Equations
- 6th-8th Grade Algebra: Systems of Linear Equations
- 6th-8th Grade Math: Properties of Functions
- 6th-8th Grade Math: Graphing Functions
- 6th-8th Grade Math: Solving Math Word Problems
- 6th-8th Grade Measurement: Perimeter & Area
- 6th-8th Grade Geometry: Introduction to Geometric Figures
- 6th-8th Grade Geometry: Angles
- 6th-8th Grade Measurement: Units of Measurement
- 6th-8th Grade Geometry: Quadrilaterals
- 6th-8th Grade Geometry: Circles
- 6th-8th Grade Geometry: Circular Arcs & Measurement
- 6th-8th Grade Geometry: Polyhedrons & Geometric Solids
- 6th-8th Grade Geometry: Symmetry, Similarity & Congruence
- 6th-8th Grade Geometry: Transformations
- 6th-8th Grade Geometry: Triangle Theorems & Proofs
- 6th-8th Grade Geometry: Similar Polygons
- 6th-8th Grade Geometry: The Pythagorean Theorem
- 6th-8th Grade Math: Data & Graphs
- 6th-8th Grade Math: Probability
- 6th-8th Grade Math: Statistics
- 6th-8th Grade Math: Rates, Ratios & Proportions
- 6th-8th Grade Math: Money
- 6th-8th Grade Math: Consumer Math
- 6th-8th Grade Math: Number Sequences
- 6th-8th Grade Math: Sets
- 6th-8th Grade Algebra: Monomials & Polynomials