Curated OER
What are Acute, Obtuse, Right, and Straight Angles?
Angles are identified by the measurement of their angles. Well, that would make sense. The instructor illustrates four different angles and their names by identifying their degrees. Zero to less than 90 degrees is an acute angle, while...
Sophia Learning
Sophia: Triangle Angle Combinations: Lesson 5
This lesson explains how you can have 3 acute angles, 1 obtuse and 2 acute angles or 1 right and 2 acute angles in a triangle. It is 5 of 7 in the series titled "Triangle Angle Combinations."
Virtual Nerd
Virtual Nerd: What Is a Triangle?
This tutorial explains triangles and their different types. [5:58]
Virtual Nerd
Virtual Nerd: How Do You Classify Triangles?
If you know what kind of triangle you're looking at, it's much easier to figure out how to solve for various sides and angles. Use this tutorial to practice classifying triangles. [7:15]
Virtual Nerd
Virtual Nerd: How Do You Classify Triangles?
This tutorial provides practice in classifying triangles which is useful when figuring out how to solve for various sides and angles. [7:15]
Math Antics
Math Antics: Triangles
Gain a basic understanding of triangles by watching easy to understand video tutorial. Additional resources are available as part of a paid subscription service. [7:39]
Khan Academy
Khan Academy: Angles: Using a Protractor
Shows how to use a protractor to measure an angle. Identifies different types of angles: acute, obtuse, right.
Sophia Learning
Sophia: Triangle Angle Combinations: Lesson 4
This lesson explains how you can have 3 acute angles, 1 obtuse and 2 acute angles or 1 right and 2 acute angles in a triangle. It is 4 of 7 in the series titled "Triangle Angle Combinations."
Sophia Learning
Sophia: Triangle Angle Combinations: Lesson 1
This lesson explains how you can have 3 acute angles, 1 obtuse and 2 acute angles or 1 right and 2 acute angles in a triangle. It is 1 of 7 in the series titled "Triangle Angle Combinations."