#!/usr/bin/env ruby
# -*- coding: utf-8 -*-

module Menseki
  def sankaku(tei, tak)
    tei.to_f * tak / 2
  end
  def daikei(jotei, katei, tak)
    (jotei+katei)*tak/2.0
  end
  module_function :sankaku, :daikei
end

if $0 == __FILE__
  p Menseki.sankaku(3,4)
  p Menseki.daikei(3,4)
end