From the biggest to the smallest: the biggest planets of the Solar System are the gas giant Jupiter and something smaller the planet famous for its rings, Saturn. Similar in size and half the diameter of Saturn are Uranus and Neptune. Much smaller than the previous and also similar to each other are Earth and Venus. They are followed by Mars, Mercury and finally Pluto, which has half the diameter of Mercury and is on the border between what is a planet and a dwarf planet.
Order of placement: Jupiter - Saturn - Uranus - Neptune - Earth - Venus - Mars - Mercury - Pluto
Its position with regard to the Sun
In the center we put the Sun that generates energy and illuminates us.
Then place the inner planets closest to the Sun, and that are smaller and rockier, inthe order indicated: 1º Mercury, 2º Venus, 3º Earth and 4º Mars.
Further away from the Sun, now place the large, gaseous outer planets: 5º Jupiter, 6º Saturn, 7º Uranus, and 8º Neptune.
Finally and the farthest from all is Pluto that is so small that according to different criteria sometimes it is considered as a planet, and sometimes not (dwarf planet).