It is 8.525. what u do is 21÷40 and get .525 and then u add the 8 in the front and get 8.525
16-gon = 2,520 deg
2,520 divided by 16 = 157.5
157.5 deg
A 40 degree angle: go from the right positive side of the x-axis and go left (left is positive degrees) forty degrees, which is a little less than halfway in quadrant 1.