William is building a planetary path for people to walk alone. The planetary path will have a model of the sun and models of the planets. William uses two scales. He used 1 cm to 1000km for the diameter of each planet. 1cm to 1000 000km for the distance from the sun to each planet. William makes a model of the planet Venus. The model had a diameter of 12.1 cm. Work out the real diameter of the planet Venus. Give in standard form.