A quadrilateral is a 4-sided plane figure. It has no volume. The area of a regular quadrilateral is the square of the length of its side.
The volume of a parallelepiped is the product of its height and the area of its base. The volume of a regular parallelepiped is the cube of the length of its side.
The volume of a parallelepiped is the product of its height and the area of its base. The volume of a regular parallelepiped is the cube of the length of its side.