They had used them for feet! Hope this helped:)
their sail like fins are to help them with body temperature
Pelycosaurus, specifically the well-known genus Dimetrodon, likely used its sail-like fins for thermoregulation, helping to absorb heat from the sun or dissipate excess heat. This adaptation would have allowed them to maintain optimal body temperatures in varying environmental conditions. Additionally, the sail may have played a role in display and mating behaviors, signaling fitness to potential mates or rivals.
Sailing has been around since prehistoric times, therefore the name of the person who made the first sail boat is not recorded.
It was amargasaurus which was a type of sauropod
he was an explorer! of course he would have liked to sail.
Like that! If it were sail as in I sailed a cross the sea you could put you are a sailor you can SAIL very well. But if it was sail as in the sail on a ship, you could put the SAIL on the ship was ripped. And so on. Hope I answered your question xx
Water like the sea or lakes, but the sails sail on the wind and air. Hope this is the answer you were looking for!
Wut made ships sail in the wind was that using a persicet sail or flag will pick up the wind and will push the air out and sail..just like u swinging on a swing 
The lateen sail looks like a triangle. The point is on one side and the base is on the other side. The base of the sail would be parallel to the main mast. A spar at the top of the sail is attached to the mast. It is mainly used on sunfish and other extremely small sailing craft.
because they sail on ships.
Paragliding aerofoils.
because he felt like it