How do you find the measure of degrees of a octagon?

Octagon = 8 sides, 8 angles.

If it is a regular octagon, then use the sum of angles formula, (n - 2)180°, where n is the number of sides.

(n - 2)180° = (8 -2)180° = 6 x 180° = 1,080°

Thus each angle is 135° (1,080/8).