Shape of solid below z=3-y, above the xy plane, and bounded on the sides by the cylinders y=x^2 and y=2-x^2. restart: with(plots): Define the TOP, SIDE, and the BOTTOM surface plots. Note (a) variable myrange defined to avoid typing range 3 times. (b) range for x, y, and z chosen arbitarily - modify the range once a rough plot is obtained. (c) different color used for each surface. myrange := x=-2..2, y=-2..2, z=0..2; top := implicitplot3d( z=3-y, myrange, color=blue ); side1 := implicitplot3d( y=x^2, myrange, color=red); side2 := implicitplot3d( y=2-x^2, myrange, color=yellow); bottom := implicitplot3d( z=0, myrange, color=green ); Now display the surfaces. display( {top, side1, side2, bottom}, style=patch, axes=boxed, orientation=[25,60]); It seems that the range for x, y, is TOO WIDE and the range for z is not high enough. What should range be to obtain a nicer picture? Try it.