Question 36266
What is the measure of each angle of a regular polygon with 6 sides?

Draw the figure.
Connect each vertex to the center forming 6 triangles.
The sum of the angles of all six triangles is 6(180)
But the sum of the six central angles is 2(180)=360
So the sum of all the interior angles is (6-2)180 = 720 degrees.
That sum is evenly divided by the 6 interior angles 
So, each interior angle has measure 720/6 = 120 degrees.
Cheers,
Stan H.