Answer:
The prism is 3 by 3 by 1.5.
Explanation:
The prism has a length x and a width x. Since it is a square at the base both length and width are the same amount x. The height is "half the length of one edge of the base". Since the base is x, this makes it 1/2x.
The volume's prism is found using V = l*w*h. Substitute and simplify.
13.5 = x*x*1/2x
13.5 = 1/2 x^3
27 = x^3
3 = x
The prism is 3 by 3 by 1.5.