Trigonometric Functions question. "What is the length of side BC? *Picture in comments*

Question

anonymous · Answer

attachment

tkhunny · Answer

This is a wonderful application of the Tangent function.  What's your plan?

anonymous · Answer

I don't necessarily have a plan. I'm completely stuck.

tkhunny · Answer

Did you miss the hint?  Try the Tangent function.

shortystudys · Answer

20degrees

tkhunny · Answer

Why would the side of a triangle be measured in degrees?  It's a length.

You must memorize this:  Given an angle, A, and a Right Triangle, ABC, $tan(A) = \dfrac{Opposite}{Adjacent} = \dfrac{mCB}{mAB}$.

shortystudys · Answer

I didn't mean to say degrees x''D

tkhunny · Answer

Legs are the same size in a 45-45-90 right triangle.  You don't have one of those.

How did you use the tangent function?