Central Angle Exploration

The goal of this activity is to determine the relationship (and ultimately the equation) between the number of sides of a regular polygon and the measure of the central angle.
1) What is the formula to determine the measure of a central angle of a regular polygon if the number of sides is n.? 2) If there are 20 sides, what is the measure of the central angle? 3) If the central angle is 12 degrees, how many sides does the regular polygon have?