Flipped Math
Reference Triangles
It is all about where the side is located. Pupils use their knowledge of angles in standard position to find reference angles. They use the Pythagorean Theorem to find lengths along a terminal side of an angle to determine the exact...
Project Maths
The Unit Circle
It's not just any circle—it's the unit circle. The fourth instructional activity in the series is an introduction to the famous unit circle. While working through a series of activities, young scholars learn the components of the unit...
Alabama Learning Exchange
Unit Circle: Special Angles—Just Know One
It's all about the patterns! Young scholars learn that the unit circle repeats itself in all four quadrants. Using these patterns, they evaluate the sine, cosine, and tangent of special angles.
CK-12 Foundation
Reference Angles and Angles in the Unit Circle: Exploring Reference Angles
A steal of a deal — get four angles for the value of one. An interactive resource allows individuals to visualize all four angles that have the same reference angle. Pupils answer questions by using the interactive to create the...
CK-12 Foundation
Measuring Rotation: Aircraft Headings
Measure angles in more than one way. The interactive introduces the concept of measuring angles from 0 to 360 degrees. Scholars explore the relationships between the angle and reference angles along with coterminal angles.
EngageNY
Extending the Domain of Sine and Cosine to All Real Numbers
Round and round we go! Pupils use reference angles to evaluate common sine and cosine values of angles greater than 360 degrees. Once they have mastered the reference angle, learners repeat the process with negative angles.
Curated OER
Practice Problems
In this geometry instructional activity, students practice finding the measure of 4 different angles. Students work independently as they refine their ability to correctly calculate the measure of an angle.