Quadrantal Angles

The Pythagorean Theorem is a staple of middle school geometry. Scholars first investigate angle relationships, both in triangles and in parallel lines with a transversal, before proving and applying the Pythagorean Theorem.

This extensive chapter gives learners a new angle on that old geometry favorite, trigonometry. From the unit circle to right triangles, the role of trigonometric ratios is explored through explanation of theory and working application...

Calculate exact trigonometric values using the angles of special right triangles. Beginning with a review of the unit circle and trigonometric functions, class members use their knowledge of special right triangles to find the value of...

Here's an algebra II activity that strives to make the concept of a radian less abstract and more conceptual. It takes a hands-on approach to exploring the idea of a radian and allows individuals to develop a definition of a radian...

Your learners connect the new concepts of transformations in the coordinate plane to their previous knowledge using the solid vocabulary development in this unit. Like a foreign language, mathematics has its own set of vocabulary terms...

Can you use triangles to create a circle? Learners develop the unit circle using right triangle trigonometry. They then use the unit circle to evaluate common sine and cosine values.

Your young trigonometry learners will analyze and discover the many valuable relationships on the Unit Circle in this very rich collaborative task. Using co-terminal and reference angles in degrees and radians, learners find and label...

Put the triangle back in trigonometry, and show learners how the unit circle is built up of right triangles. Taking the skills they know from the first quadrant, the class discovers that these values repeat in all of the quadrants by...

While many classes memorize the radian and degree relationships for special angles in the unit circle, this presentation is uniquely grounded in the "why's" behind these common angles. With an emphasis on the geometric interpretation of...

Learn how to measure the reference angles in degrees and radians.  Students find reference angles that are coterminal with a given angle.