Explore acute triangles with this handy reference guide. Provides a detailed definition and an interactive activity that enhances further explanation. Includes links to related topics.

A reference guide to obtuse triangles. It provides a definition and interactive animated activity that enhances further explanation.

Learn about the types of triangles by taking a look at an example and a video lesson.

An introduction to solving acute and obtuse triangles by using the law of sines, including a derivation of the formula. Includes several pictures and examples.