How do you draw a pie chart using a tally table?

Suppose there are n groups and the number of tallies for the nth group is tn.

Find T the grand total of the tallies. So that T = t1 + t2 + ... + tn

Then

the angle of the first segment of the pie chart should be 360*t1/T degrees;

the angle of the second segment of the pie chart should be 360*t2/T degrees; etc.