Triangle facts feature

Trying to avoid a long series of puts statements

Alternatively, you could have something that classifies the type & returns a symbol that could be used as a lookup in a hash of messages. 

https://github.com/jmmastey/level_up_exercises/pull/171
Why not use side1, side2 & side3 instead of the array indices?. Definitely use 2 instead of 2.0. Consider shortening radians_to_degrees to rads_to_degrees, rads is an acceptable abbreviation. Not sure that degrees has one.