Hello there.
We have for a circle that:
Where:
is the measure of the arc
is the measure of the angle (radians)
is the radius of the circle
In our case, we have 
We have r = 3 cm, then:
Answer:
The median is usually preferred in these situations because the value of the mean can be distorted by the outliers. However, it will depend on how influential the outliers are. If they do not significantly distort the mean, using the mean as the measure of central tendency will usually be preferred.
