Curated Video
Solving Non-Right Triangles Using the Law of Sines
In this video, you will learn how to find the missing side lengths of a non-right triangle using the Law of Sines. The Law of Sines relates the angle measures and side lengths of an oblique triangle.
Curated Video
Using Interior and Exterior Angles to Find Unknown Angle Measures
In this video, students are taught how to find unknown angle measures using interior and exterior angles. The concept of supplementary angles is introduced, and a common mistake regarding the sharing of vertices is addressed.
Getty Images
WS T/L PAN View of Lake Starnberg / Wolfratshausen, Bavaria, Germany
WS T/L PAN View of Lake Starnberg / Wolfratshausen, Bavaria, Germany
Curated Video
Alaska's Famed Iditarod To Begin Amid Turmoil
The 46th running of Alaska's famed Iditarod Trail Sled Dog Race kicks off Saturday amid the most turbulent year ever.
Among the problems: a doping scandal, the loss of a major sponsor and escalating pressure from animal...
Curated Video
Alaska's famed Iditarod sled dog race to begin amid turmoil
The 46th running of Alaska's famed Iditarod Trail Sled Dog Race kicks off Saturday amid the most turbulent year ever.
Among the problems: a doping scandal, the loss of a major sponsor and escalating pressure from animal...
Curated OER
What is a Triangle?
Triangles, triangles, triangles. What makes a polygon a triangle? How many types of triangles are there? How do you determine what kind of triangle it is? Watch this video as the teacher explains 'tri' meaning three, making a triangle -...
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...
Curated OER
What are Supplementary Angles?
What are supplementary angles? They are two angles that when added together make 180 degrees on a straight angle line. Hard to picture that? Then watch this video and see how the instructor illustrates this on a diagram.
Curated OER
How Do You Use Supplementary Angles to Find a Missing Angle?
How can a straight line be called a straight angle? Can angles be combined to form a straight angle? Yes, supplementary angles can be combined to make a straight angle and that is how one can find the value of a missing angle. Take a...
Virtual Nerd
What is the Triangle Sum Theorem?
If you add the value of the three interior angles in a triangle will it equal 180 degrees? Yes it will. The instructor illustrates and proves the Triangle Sum Theorem. Follow closely as she explains her proof.
Virtual Nerd
Virtual Nerd: What Are Equilateral, Isosceles, and Scalene Triangles?
Watch this tutorial to learn about some of the different kinds of triangles. [5:33]
Virtual Nerd
Virtual Nerd: What Is a Transversal?
This tutorial introduces transversals and shows what happens when a transversal meets two parallel lines. [6 :22]
CK-12 Foundation
Ck 12: Elem Math: Overview Sum of the Angles of a Triangle
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview on funding the sum of angles in a triangle.