Khan Academy
Khan Academy: Find Angles in Triangles
Find missing angle measures using the properties of triangles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.
CK-12 Foundation
Ck 12: Converse of the Pythagorean Theorem
[Free Registration/Login may be required to access all resource tools.] Learn about the converse of the Pythagorean Theorem and some of its applications. Also explains how to identify acute and obutse triangles through the use of the...
Education Place
Houghton Mifflin: Eduplace: What Is It? Pythagorean Theorem
This is a great place for information on the Pythagorean Theorem. Three other sections (tabs at the top) are available, including tips, students' questions, and lesson ideas.
Free Math Help
Free Math Help: Exterior Angle of a Triangle
This tutorial discusses exterior angles of a triangle. Example problems with explanations are included.
McGraw Hill
Glencoe: Self Check Quizzes 2: The Pythagorean Theorem
Test your knowledge of the Pythagorean Theorem with these practice problems. Each question has a "Hint" link to help. At the bottom of the page click the "Check It" button and the correct answer for each problem appears beside it. Also,...
Wolfram Research
Wolfram Math World: Similar Triangles
Find the necessary information to decide if triangles are similar at this MathWorld site.