The side faces of a pyramid are:
(A) Triangles
(B) Squares
(C) Polygons
(D) Trapeziums
Pyramid:
We know that a pyramid is formed by connecting a polygonal base and a point called the apex. It is a conic solid with a polygonal base and triangular sides.
Hence the side faces of a pyramid are always triangles.
For example,
From left to right: Cone or circular pyramid, Triangular pyramid, Rectangular pyramid, Pentagonal pyramid