  Surface area and mean width of a cylinder (the convex hull of two parallel
disks) in R^3 are computed. It is more difficult to obtain analogous results
for a cone (the convex hull of a disk D and a point p). Oblique formulas for
mean width, as well as those for mean curvature, are new. Let L denote the
unique diameter of D whose endpoints are equidistant from p. We conclude with a
question involving the plane that bisects the cone and contains {p,L}, as p
varies. What is the minimum ratio of the smaller measure to the larger?
