You are given two interior angles (in degrees) of a triangle.
Write a function to return the 3rd.
Note: only positive integers will be tested.
https://en.wikipedia.org/wiki/Triangle
def other_angle(a, b)
180-(a+b)
end
def first_non_consecutive(arr)
arr.each_index do |i|
return arr[i + 1] if arr[i].next != arr[i + 1]
end
end