model-size.rb

UI.menu("Extensions").add_item("Print Model Size") {
   JF::ModelSize.main
}

module JF
   module ModelSize
      def self.main
         bb = Sketchup.active_model.bounds

         # 8.times {|c|
         #    Sketchup.active_model.entities.add_cpoint(bb.corner(c))
         # }
         print "Model size: ["
         print (bb.corner(1).distance(bb.corner(0))).to_s, " x "
         print (bb.corner(2).distance(bb.corner(0))).to_s, " x "
         print (bb.corner(4).distance(bb.corner(0))).to_s, "]\n"
      end
   end
end