Khan Academy
Khan Academy: Special Right Triangles
Use your knowledge of 30-60-90 and 45-45-90 triangles to solve some problems.
Lawrence Hall of Science
The Math Page: Trigonometry: The 30 60 90 Right Triangle
Here is a site that clearly and thoroughly explains the trigonometry of the 30-60-90 right triangle. There are example problems solved, problems for the student to attempt, and answers to the student problems. Point this site out to...
OER Commons
Oer Commons: Classifying Triangles
In this lesson plan, students learn to classify triangles by the size of the angles and the measures of the sides. Students will use interactives to explore equilateral, isosceles, scalene, acute, obtuse, and right triangles. Included...
Clark University
Clark University: Dave's Short Trig Course: Tangents and Slopes
Explains what "tangent" is and its role in the right triangle. Slope of a line is investigated and tangent for special common angles is given. Angle of elevation and angle of depression are also covered here.