Sophia Learning
Sophia: Triangle Interior Angles Practice: Lesson 5
This lesson provides practice problems that involve the sum of the interior angles of triangles. It is 5 of 6 in the series titled "Triangle Interior Angles Practice."
Sophia Learning
Sophia: Triangle Interior Angles Practice: Lesson 1
This lesson provides practice problems that involve the sum of the interior angles of triangles. It is 1 of 6 in the series titled "Triangle Interior Angles Practice."
Texas Instruments
Texas Instruments: Triangle Sum
This activity is used to discover that the sum of the measures of the triangle angles is constant and to discover ways of proving the theorem listed in the activity.
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."
Purple Math
Purplemath: The Pythagorean Theorem
Defines the Pythagorean Theorem, and demonstrates how to use this Theorem in connection with right-angled triangles.
Other
Brown Math: Remembering Trig Identities
Faced with a large number of trigonometric identities, students tend to try to memorize them all. This site the emphasis is on understanding how the functions work and on memorizing only about a half dozen of them - all the others work...
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.