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)
  # WRITE THIS CODE
  s = (a + b + c) / 2.0
  valid_traingle = (s - a) * (s - b) * (s - c) # To check if it's a valid triangle

  if a <= 0 || b <= 0 || c <= 0 || valid_traingle <= 0
    raise TriangleError
  end

  equilateral_conditions = (a == b && b == c)
  isosceles_conditions = (a == b || b == c || a == c)

  if equilateral_conditions
    return :equilateral
  elsif isosceles_conditions
    return :isosceles
  else
    return :scalene
  end
end

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