The measures all add up. The presentation, part of a helpful playlist on geometry, provides the statement of the Triangle Sum Theorem. Using the theorem, the video shows how to find the missing measure of an angle.

For your eyes only: classify the names of polygons. After providing the definition of a polygon, the video introduces the two major classifications of polygons, concave and convex. The segment of a larger playlist on geometry continues...

How did polygons get their name? A brief video in the Socratica Geometry series explains the naming convention for polygons. Of course, this occurs after defining the term polygon.

Base your calculations of the areas of triangles on their bases. An illuminating video in the Socratica Geometry playlist explains how to determine the areas of a triangle. The video uses an animation to illustrate how triangles with the...

What shapes classify as a polygon? The resource provides the definition of a polygon and provides examples of polygons and shapes that are not polygons. The presentation gives an explanation of why each shape falls into the particular...

What has three sides and is adorable? A-cute triangle. The resource introduces triangles and how to classify them by sides and angles or both. The video concludes with using the sum of the angles of a triangle to show how to solve for a...

Showing is better than telling in a short demonstration video to find the area of a circle. The silent narrator transforms the circle, made from ball chain, into a triangle you can measure with a ruler, labeling quantities each...

No one wants to pay more for rent than they need to. Here is a video where future renters can learn how to fairly split rent with roommates based on room preferences. An explanation of the Sperner's lemma using an simplex isn't as...

Sing along to a simple, yet informative, music video featuring eight shapes—square, circle, triangle, rectangle, star, heart, oval, and diamond.

Show your class that finding angle measures is a regular calculation with a resource that provides 12 problems dealing with the measures of angles in regular polygons. Pupils use formulas for the sum of measures of angles in a polygon to...

Using patterns to build a formula is an important mathematical skill. Pupils discover a formula to find the sum of interior angles in a polygon by analyzing a pattern. The additional videos show how to use the formula to find various...

Get to know the triangle, circle, and square with a music video filled with hand-drawn animation set to a laid back beat. 

Need to find the length of a side of a right triangle? Just use the Pythagorean Theorem! Follow along as the tutor defines the Theorem, explains how it works, then uses it to determine the missing length of a right triangle. 

Is prism just another mathematical term for a solid? It must be since this lesson is about volume. The teacher illustrates and explains how to find the volume of a rectangular prism and also how to find the volume of a triangular prism....

A trigonometric ratio is a ratio between two sides of a right triangle. In this problem, find sin(A) in the given right triangle. Use the ratio of the opposite side over the hypotenuse.

What are all the parts of a right triangle called? What makes it a right triangle? Legs? Triangles have legs? Hypotenuse? Pythagorean Theorem? The instructor diagrams and identifies all the parts of a right triangle for you.

Three angles of one triangle are equal to the corresponding angles in another triangle. Use a ratio of corresponding sides to find the scale factor. Actually, there are two scale factor values. The instructor will explain how to get both...

Instruct your class on how to find the volume of a triangular pyramid using this tutorial. Learners can watch the video and take notes, later applying what they have seen to class work or homework. A clear video with direct instruction,...

Did you know you can use the Pythagorean theorem to find the slant height of a cone? You can! Just watch this tutorial and see how you can find the lateral and surface area of a given cone using slant height and the Pythagorean theorem.

The formula for the area of a triangle is: area equals one half the base times the height. If you have been given these two values then all you need to do is plug them into the formula and solve. Don't forget to write the correct ending...

Trapezoids can be tricky! Break down the process of finding the area of a trapezoid with an engaging math video. Learners explore area formula and shown exactly how to plug in information, solve, and simplify. 

Learn how to identify an equilateral triangle by evaluating its congruent sides. Once you've determined that that sides are congruent you'll be able to use the triangle sum theorem to determine the angles in an equilateral triangle. This...

Are you working on finding the missing angles of triangles in your class? Consider this video. An instructor uses the triangle sum theorem to create an equation that helps her find the missing angles. She explains each step and writes...

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 -...