Curated OER
Trigonometry Review Sheet
Get the trig facts fast, and use the review sheet as a guide in the classroom. The worksheet also includes a document version if any changes are needed to the problems. The information includes a small degree/radian chart, a graph of all...
Math Open Reference
Math Open Reference: 30 60 90 Triangle
Learn about the 30-60-90 triangle with this helpful reference tool. Provides a detailed definition, examples, and an interactive activity that enhances further explanation. Includes links to related topics.
Purple Math
Purplemath: Special Angle Values: 30 60 90 and 45 45 90 Triangles
Explains a simple pictorial way to remember basic reference angle values. Provides other memory aids for the values of trigonometric ratios for these "special" angle values, based on 30-60-90 triangles and 45-45-90 triangles.
CK-12 Foundation
Ck 12: Geometry: Special Right Triangles Study Guide
[Free Registration/Login may be required to access all resource tools.] Different types of right triangles and trigonometric ratios for special right triangles are covered in this study guide.
Geometry Help
Geometry Help: Right Triangles
Explains the basic concept of right triangles with step-by-step instructions and methods for solving specific problems on your own relating to this topic.