the base of a right cylinder is shown in the figure(not included). it is formed by describing semicircular arcs within the square upon the four sides as diameters. the square has 4 inches side. if the altitude of the cylinder is 12 inches, find the volume and total area.
the area of a semicircle of radius 2 is 2pi
the areas of all 4 semicircles is 8pi
the area of the square is 9
the volume of the cylinder with the star-shaped cross-section is (9 - 8pi)*12