# Radians: Measuring Angles using Arc Length

- Author:
- shanlee

- Topic:
- Angles

1. Drag the slider to change the radius. Move the Point to change the size of the angle.
a). How does changing the radius affect the angle size?
b). How does changing the radius affect the arc length?
2. Move the Point to create an angle of 1 radian measure.
a). Change the radius. What do you notice?
b). If an angle is 3 radians in size, what type of angle is it? Acute, obtuse or reflex?
3. Write down what you think 180 degrees in radian angle measure would be.
Then use the app to check your response.