Answer:
Step-by-step explanation:
a) The sum of the interior angles of a polygon with sides is equal to . Since an octagon has 8 sides, substitute in :
b) The sum of the exterior angles for any polygon is equal to .
c) By definition, all regular shapes have equal angles and sides. Since we've found the total sum of the interior angles of an octagon in part a, each interior angle of a regular octagon must be
d) Similar to part c, all regular shapes must have equal angles and sides. From part b, we know the sum of the exterior angles of a octagon is , thus we have