Measurement.define(:'yd²') do |unit|
  unit.alias :yd2, :'yd*yd', :'sq yd', :'square yard', :'square yards'
  unit.convert_to(:mi2) { |value| value / 3_097_600.0 }
  unit.convert_to(:fur2) { |value| value / 48_400.0 }
  unit.convert_to(:ch2) { |value| value / 484.0 }