A triangle
Rectangle
a pyramid where each face is the shape of a triangle
rectangular prism pyramid
a triangle
The shape you are describing is a triangular pyramid. A triangular pyramid has a base that is a triangle and three triangular faces that meet at a single point called the apex. The base of the pyramid is a rectangle, which is a quadrilateral with four right angles. The triangular faces of the pyramid connect the vertices of the base to the apex.
a pentagonal pyramid
Triangular Prism, Triangular Pyramid.
A polyhedron as for example a pyramid
a square based pyramid.
A prism or a pyramid
If the base of the pyramid is a triangle then all its faces would be triangular in shape.