Ruby Koan 151 raising exceptions

Question

I\'m going through the ruby koans, I\'m on 151 and I just hit a brick wall.

Here is the koan:

# You need to write the triangle method in the file \'trian         


        

Answer 1

Rules:

1. size must be > 0

2. Total of any 2 sides, must be bigger that the 3rd

Code:

raise TriangleError if ( [a,b,c].any? {|x| (x <= 0)} ) or ( ((a+b)<=c) or ((b+c)<=a) or ((a+c)<=b))
[:equilateral, :isosceles, :scalene].fetch([a,b,c].uniq.size - 1)