Circle Graphs

Month | Snowfall | Percent | Angle Measure
November | 1 | ? 1% | ? 3.6
December | 4 | ? 4% | ? 14.4
January | 5 | ? 5% | ? 18
February | 2 | ? 2% | ? 7.2

How would I make a circle graph? Or did I do something wrong? The month and snowfall were given and I found the percent and angle measure.

You need to consider the total snowfall: 12 inches.

November had 1/12 or 8.3% of the total
Do the other months likewise.

For a circle graph, all the sections need to add up to 100%.