



 
Hi Kenn, I drew a diagram of what you described. The volume of a circular disk is π r^{2} t where r is the radius ant t is the thickness. Since this is concrete I expect you want the volume in cubic yards so you should first convert the measurements to yards. There are 3 feet in a yard so the radius is 8/3 yards and there are 36 inches in a yard so the thickness is t/36 yards. Thus the volume is
Hence if the base is 5 inches thick the volume is 0.16 ×5 = 0.78 cubic yards. Harley  


Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences. 