First things first:
What are wide angle lenses for?
As I often try to emphasize during my courses, lenses are ‘translators’, magical devices that allow us to turn 3D reality into a 2D image. We are born with one pair and take we mostly take them for granted. Our eyes are wondrous evolutionary accidents and they show us the world in a way that we assume to be the standard. It is lenses that allow us to see the world in a different way! When you get a new lens it opens up a completely new visual universe in much the same way that people who speak foreign languages can become immersed in new realities.
If you have a full frame camera, your standard lens is the 50mm, if it’s a cropped sensor one (like the Nikon 3xxx, 5xxx or 7xxx DSLRs or Canon’s 600D, 700D, 60D, 70D) it is the 35mm lens. (If this distinction is not completely clear, have a look at this article I’ve written on the topic of the crop factor.)
Wide angle lenses translate space in a striking way: objects that are close to the lens appear to be much bigger than objects that are in the background. The wider the lens (i.e. the larger it’s field-of-view is) and the closer the object is the more exaggerated this effect is.