1. 6.1.3 Unit Circle, Special Angles

2. Building the “Unit Circle” For the unit circle, we will look into attempting to define and build the circle in terms of radians We can discover a pattern which will help you easily convert/memorize the patterns

3. Special Triangles; 45-45-90 The special 45-45-90 triangle is one special triangle which will help us 1-1-√2 ratios What is 45 0 in radians? 90?

4. Special Triangles; 30-60-90 The 30-60-90 will also help us Same type of relationship 1-2-√3 ratios What is 30 0 in radians? What is 60 0 in radians?

5. Now, we can look at the unit circle as: – 1) A series of 45-45-90 triangles – 2) A series of 30-60-90 triangles We can split the unit circle into these 30-60-90 triangles and 45-45-90 triangles

6. Positive/Negative Angle Measures On the unit circle, we can measure a positive or negative angle, depending on the direction of measurement Clockwise = Negative Angle Measure Counter-Clockwise = Positive Angle Measure

7. Example. Find the indicated angle measure.

10. The Whole Unit Circle

11. Assignment Pg. 466 45-56 alls