code: def _draw_background(self, divisions=10):
          
          self.canvas.create_arc(2, 2, self.size-2, self.size-2,
                                 style=tk.PIESLICE, start=-60, extent=30,
                                 fill='red')
          self.canvas.create_arc(2, 2, self.size-2, self.size-2,
                                 style=tk.PIESLICE, start=-30, extent=60,
                                 fill='yellow')
          self.canvas.create_arc(2, 2, self.size-2, self.size-2,
                                 style=tk.PIESLICE, start=30, extent=210,
                                 fill='green')
  
          # find the distance between the center and the inner tick radius
          inner_tick_radius = int(self.size * 0.4)
          outer_tick_radius = int(self.size * 0.5)
  
          for tick in range(divisions):
              angle_in_radians = (2.0 * cmath.pi / 3.0) \
                                 + tick/divisions * (5.0 * cmath.pi / 3.0)
              inner_point = cmath.rect(inner_tick_radius, angle_in_radians)
              outer_point = cmath.rect(outer_tick_radius, angle_in_radians)
  
              self.canvas.create_line(
                  *self.to_absolute(inner_point.real, inner_point.imag),
                  *self.to_absolute(outer_point.real, outer_point.imag),
                  width=1
              )
docs: Draws the background of the dial
  
          :param divisions: the number of divisions
          between 'ticks' shown on the dial
          :return: None