Answer:
12ft
Explanation:
A prism is a 3D shape which has the same 2D shape repeated along its length (this is sometimes called the cross section).
The 2D shape at the ends of the prism is the base of the prism, so for this shape, the bases are the triangles.
The height of the prism is actually the length of the prism, so for this prism the height is 12 ft.