On a circle graph, if the data represents x%, it corresponds to x% of 360 degrees.
For example, if a data represents 50%, a circle has 360 degrees, then it must be 50% of 360 degrees allotted for that data. Then, in fact, we are going to do x% of 360º for each category:
Less than 1 hour: 8% of 360 degrees
1-2 hours: 29% of 360 degrees
2-3 hours: 58% of 360 degrees
3-4 hours: 3% of 360 degrees
Over 4 hours: 2% of 360 degrees.
Now we need to do all that calculus:
Hence,
Less than 1 hour: 28.8 degrees
Doing that for each category:
1-2 hours
1-2 hours: 104.4 degrees
2-3 hours
2-3 hours: 208.8 degrees
3-4 hours