Below are some outside links which clarify the relationship between the sensor or film format and the angle of view/ field of view:
Angle of view
http://en.wikipedia.org/wiki/Angle_of_view#Derivation_of_the_angle-of-view_formula

Field of view
http://en.wikipedia.org/wiki/Field_of_view

Lens
http://en.wikipedia.org/wiki/Photographic_lens

• Normal lens: angle of view of the diagonal about 50° and a focal length approximately equal to the diagonal produces this angle.
• Macro lens: angle of view narrower than 25° and focal length longer than normal. These lenses are used for close-ups, e.g., for images of the same size as the object. They usually feature a flat field as well, which means that the subject plane is exactly parallel with the film plane.
• Wide-angle lens: angle of view wider than 60° and focal length shorter than normal.
• Telephoto lens or long-focus lens: angle of view narrower and focal length longer than normal. A distinction is sometimes made between a long-focus lens and a true telephoto lens: the telephoto lens uses a telephoto group to be physically shorter than its focal length.