Klein Bottle:
http://en.wikipedia.org/wiki/Klein_bottle
Its circle
A hemisphere has 1 circular face and one which is half the surface of a sphere.
sphere
sphere
pentagonal pyramid
A cone would fit the given description
a sphere
Sphere, torus, moebius strip
legnthXwidthXheight Top is close, but only for a rectangular prism :(... It is actually (base area) X height. For pyramids, it is 1/3(base area) X height.
its a lens...1 curved edge = a circle, 1 flat surface = back, 1 curved surface = front. (these are used in some battery-less flashlights, as an example.)
Spherical
A cone, a sliced ellipsoid (including sphere) are two possibilities. There are others.
A hemisphere