posted by suzie on .
If you put two dodecagons together with another polygon that will exactly surround a point what type of polygon could be used?
Recall that the exterior angles of a regular polygon add up to 360°.
So for a dodecagon (12 sides), the exterior angle is 360/12=30°.
Two dodecagons back to back will give 2*30=60° left over.
The number of sides of the regular polygon that will fit the bill