Classification of the pyramids

• Regular pyramid: It has a regular polygon as its base and its side faces are equal.

• Irregular pyramid: It has a base that is a convex polygon.

• Convex pyramid: Its base is a convex polygon.

• Concave pyramid: It has a base that is a concave polygon.

• Straight pyramid: all its side faces are isosceles triangles and the height falls down to the average point of the base.

• Oblique pyramid: It has one side face that is not an isosceles triangle.