Unit Circle Exploration
- Author:
- David Sladkey
- Topic:
- Angles, Circle, Trigonometry, Unit Circle
This is the Unit Circle with θ being a standard angle. Use the applet to answer the questions below.
Move the angle θ along the slider in the above Unit Circle and answer the following questions.
1. If θ is 120° then what is its reference angle?
2. If θ is 225° then what is its reference angle?
3. If θ is 330° then what is its reference angle?
4. If the reference angle is 30°, then possible values would you have for θ? There are 4 when 0<θ<360 .
5. If the reference angle is 45°, then possible values would you have for θ? There are 4 when 0<θ<360 .
6. At what θ values is the y coordinate .5? There are 2 of them for 0<θ<360 . What are the reference angles for these two?
7. Give the exact values of x, y and r when θ is 120°
8. Give the exact values of x, y and r when θ is 315°
9. Angles whose terminal side lands on an axis are called Quadrantal Angles. What are the Quadrantal Angles in this applet? What happens with the reference angle when you have a Quadrantal angle?