The measure of the interior angle of a regular polygon is 180(n-2)/n for n sides.
14.
135 = 180(n-2)/n.
135n = 180n-360
45n=360
n= 8, 8 sides
15. 166.5n=180n-360
n= 26 sides
16. Since the shape is marked as a parallelogram, the angle at D is 180-angle at A= 180-115=65 degrees.