Answer:
Octagon
Explanation:
A polygon refers to a two-dimensional closed shape consists of straight sides.
Perimeter of a polygon = 24 inches
Length of each side of the polygon = 3 inches
Number of sides of a polygon = Perimeter of a polygon ÷ Length of each side of the polygon =

An octagon is a polygon consisting of 8 sides of same dimension.
So,
Name of polygon is octagon.