Instructional Video4:47
Virtual Nerd

What are Interior and Exterior Angles of a Polygon?

6th - 10th
Break down interior and exterior angles with this video. Using a pentagon, a teacher demonstrates how to find the interior and exterior angles of a polygon. She goes on to explain a few of the properties of these angles, writing down all...
Instructional Video4:12
Curated OER

How Do You Find a Missing Angle in a Quadrilateral?

6th - 10th
Oh no, there is a missing angle in a quadrilateral. Where did it go? It didn't go anywhere, it's just missing the value of the angle. So how do you find that missing value? Use a formula of course. Everything in algebra uses a formula....
Instructional Video5:59
Curated OER

How Do You Find the Sum of the Interior Angles of a Polygon?

6th - 10th
Squares, pentagons, triangles, polygons. How is it possible to figure out the sum of the interior angles of any of these multi-faceted shapes? There's got to be a formula. Of course there's a formula. That's what algebra is all about,...
Instructional Video5:17
Curated OER

How Do You Find the Measures of Exterior Angles of a Polygon if You Know the Interior Angles?

6th - 10th
What are the exterior angles of a polygon? Polygons have exterior angles? How? Oh, extend all the lines, and find the value of each of the supplementary angles. No problem as long as one knows what supplementary angles means. Not sure?...
Instructional Video4:42
Curated OER

How Do You Find Missing Angles in a Transversal Diagram?

6th - 10th
Parallel lines with a transversal and one given value, find the value of the other seven angles. There are many geometric terms about angles and lines to know the meaning of and understand their relationship to each other. Understanding...
Instructional Video4:48
Virtual Nerd

What is the Triangle Sum Theorem?

6th - 9th
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.