Question

what is the central angle dodecagon (12-gon).

Answer 1

internal angle = 180 - (360/12) = 150
i assume you mean a regular dodecagon?

Answer 2

central angle = 30 degrees

Answer 3

A circle has 360 degrees. The dodecagon is basically partitioning or slipping this up into 12 pieces. These are triangles that all meet at the center. The angles at the center will be 30 degrees. Check with 30 degrees times 12 sides or 360 degrees.