triangle.rb

# Triangle Project Code.

# Triangle analyzes the lengths of the sides of a triangle
# (represented by a, b and c) and returns the type of triangle.
#
# It returns:
#   :equilateral  if all sides are equal
#   :isosceles    if exactly 2 sides are equal
#   :scalene      if no sides are equal
#
# The tests for this method can be found in
#   about_triangle_project.rb
# and
#   about_triangle_project_2.rb
#
def triangle(a, b, c)
  if a<=0 || b<=0 || c<=0
    raise TriangleError, "Value is <= 0"
  elsif (a+b <= c) || (a+c <= b) || (b+c <= a)
    raise TriangleError, "Values of sides do not add up to a triangle"
  elsif a==b && b==c && c==a
    return :equilateral
  elsif a==b or b==c or c==a
    return :isosceles
  else
    return :scalene
  end
end

# Error class used in part 2.  No need to change this code.
class TriangleError < StandardError
end