This site has practice with classifying triangles.

http://www.onlinemathlearning.com/types-of-triangles.html

This site investigates the exterior angles of a triangle:

http://www.freemathhelp.com/feliz-exterior-triangle.html

This site has practice with classifying triangles.

http://www.onlinemathlearning.com/types-of-triangles.html

This site investigates the exterior angles of a triangle:

http://www.freemathhelp.com/feliz-exterior-triangle.html