a salesman who's always looking for an 'angle' [=looking for a way to convince people to buy the things he is selling]
The two lines meet at a 30-degree 'angle' to each other. = There is a 30-degree 'angle' between the two lines.
The two lines form a sharp 'angle'. = The two lines meet/intersect at a sharp 'angle' (to each other).
(..) a green lantern and a power ring. Easy... easy. Now we've got an inclined plane. The force required to lift is reduced by the sine of the angle of the stairs, call it degrees, so, about half. Exactly half. Exactly half. Let's push. See, it's moving, this is easy. (..)2007 TvShow: The Big Bang Theory Title: The Big Bran Hypothesis Season: 1 Episode 2