central angles
저자: Alejandro Garcia
1. How to find values of ordered pairs on the unit circle
2. clock wise
3. counterclokwise
4. 30-60-90-special right triangle
5. pythagorean theorem
5.1. Reference angle
6. radius
7. Quadrants
7.1. unit circle
8. postive angle
9. Negative angle
10. isosceles right triangles
