Where do i go to know if the lenses on a digital camera are convex or concave?

For my science project i have to know what forms a digital camera and how a digital camera works and i have to know if the lense is a convex or concave lense!!!!

This wikipedia article has some basics about lens and camera design: http://en.wikipedia.org/wiki/Single-lens...
This one goes into a bit more detail regarding lenses: http://en.wikipedia.org/wiki/Lens_(optic...
Please note that camera lenses are made up of several layers of glass. Zoom lenses can have over a dozen layers of glass - and every glass element has a 2 sides. Some of these surfaces are convex (they bulge outward), some are concave, and some can be aspherical (they start out convex, but then have a concave dimple.) On the whole, when you add up the effect of all of the glass elements, camera lenses are usually convex.

go to google
type in key words
go from there

I go alone with OMG, but you must remember that every lens is different and made up of differing numbers of elements (as each piece of glass is called). Lenses for a DSLR will be much more highly developed than a lens for a simple compact. That is likely to be a simple triplet lens with the first element convex at the front and concave on its rear , another elements in the middle which may well be convex on the front and flat on the back and a final element which is convex on both surfaces. Many styles of lenses have been developed over the years of photography, now with the aid of CAD.