Math Trig
posted by Alisha on .
In an oblique triangle ABC, A=30 degree, and the perpendicular from C to AB is 12 inches long. Find the length of AB.

tan 30 = 12/AB

Actually, you don't say that B is at the foot of the perpendicular. All we know is that the altitude from C to AB is 12. There is nothing to say how long AB is.
In fact, we are told that ABC is an oblique triangle, indicating that it is fact not a right triangle.