What is each inner corner of a regular convex polygon if the number of sides is 12?

The polygon angle sum theorem states that the sum of the angles (a) of an n-gon is 180 ° (n – 2). Find the sum of the angles for a regular convex dodecagon (n = 12):
a = 180 degrees * (n – 2);
a = 180 * (12 – 2);
a = 180 * 10;
a = 1800 degrees.
Find the degree measure of each corner of a regular dodecagon. To do this, we divide the sums of all angles by their number:
x = a / n;
x = 1800/12;
x = 150 degrees.
Answer: Each inner corner of a 12-sided regular convex polygon is 150 degrees.