Varsity Tutors
Varsity Tutors: Hotmath: Exterior Angles
This interactive tool has student explore the topic of exterior angles of a polygon. The tool allows learners to change the number of sides to find the sum of the exterior angles of a variety of polygons.
Sophia Learning
Sophia: Using Triangles to Find the Sum of Interior Angles: Lesson 1
This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon. It is 1 of 5 in the series titled "Using Triangles to Find the Sum of Interior Angles."
Khan Academy
Khan Academy: Angles of a Polygon
Find the sum of interior angles of different polygons.
ClassFlow
Class Flow: Investigating Regular Polygons
[Free Registration/Login Required] In this lesson students are introduced to regular polygons. Students learn how to find the drawing angle of any given polygon, exterior angle, interior angle and the sum of the angles for a regular...
Varsity Tutors
Varsity Tutors: Hotmath: Graphing Calculator Practice Problems Geometry
Practice using your graphing calculator for Geometry problems. If you get stumped or if you would like to check your work, then select the View Solution button, which is located directly under each problem.
Walter Fendt
Walter Fendt: Cyclic Quadrilateral (Inscribed Quadrilateral)
A short interactive activity which allows you to move the vertices of a quadrilateral to prove that the sum of the opposite angles is 180 degrees.