A hexagonal pyramid.
It could be a pyramid shape
I need help with that too!
Two triangles can be formed by the diagonals of one vertex of a four-sided polygon.
A pyramid is a solid figure with one face that is a polygon and three or more faces that are triangles with a common vertex. Yeah, pg. 114 in the math workbook is a little hard, and the guy who answered this before me thought it was funny to improve the answer by saying the answer was 45. That's just not mature. I don't get it. Anyway, I hope you finish your homework at this rate.
A pyramid has a polygonal base with all other sides being triangles. As the Egyptians famously demonstrated, a common pyramid has a square base with four triangles meeting at a vertex, but any polygon - regular or irregular - can be used as the base of such a polyhedron.