The pyramid is a 3D figure so its sides are called edges. The number of edges depends on the type of pyramid it is and the number of triangular faces it has. The base of a pyramid can be a trilateral, quadrilateral, or any polygon shape, meaning that a pyramid has at least three triangular surfaces (at least four faces including the base).
1 Additional Answer
A pyramid has three sides that you can see and it has a base. This would technically equal 4 sides. Each side of a pyramid is a triangle. The base is in the shape of a square.