A pyramid.
pyramid
The description given fits to that of a pyramid
A tetrahedron (4 faces) or triangular bipyramid (5 faces).
A polyhedron with a polygon base and triangular sides that all meet at a common vertex is known as a pyramid. The base can be any polygon, such as a triangle, square, or pentagon, and the triangular sides are called lateral faces. The vertex where all the triangular faces converge is referred to as the apex of the pyramid. Each type of pyramid is named based on the shape of its base, such as a triangular pyramid or a square pyramid.
Pyramid
pyramid
pyramid
The description given fits to that of a pyramid
A tetrahedron (4 faces) or triangular bipyramid (5 faces).
Pyramid
A geometric figure with a polygonal base and triangular sides is called a pyramid.
A polygonal pyramid.
pyramid
triangular prisum
A triangular based pyramid would seem to fit the given description
a polygonal prism or a polygond
no, it's a pyramid