So i have what i presume to be a rather simple question, for someone anyways, but not me. I have to plot a solid circle (radius=2) on the plane z=0. Not sure how to approach this as the closest i've gotten is doing implicitplot3d(x^2+y^2=4,x=-2..2,y=-2..2,z=-2..2) however it just shows the cylinder rather than a solid circle on the z=0 plane. It needs to be in 3d so i can display another graph with it. Any ideas? Thanks in advance.