A pyramid is a 3D solid with a polygonal base and triangular faces that converge at a single point called the apex. Pyramids are named by their base shape: square pyramid (Egyptian pyramids), triangular pyramid (tetrahedron), hexagonal pyramid, etc.
The Great Pyramid of Giza has a square base with sides of ~230.4 m and a height of ~146.5 m, giving it a volume of approximately 2,583,283 m³.