Trapezoidal, actually. But the square sails were called square sails. Lateen or square could be referred to as yards.
Square sails (rectangular) were (are) called four-cornered sails.
Noway
the caravel has triangular sails as well as square sails. Square sails carried the ship forward when the wind was at its back. Triangular sails allowed the caravel to sail into the wind. the caravel was better than other euoopean ships of the time at this type of sailing
Square sails are not truly square but rectangular with a longer long side on the bottom perimeter of the sail. They were and are referred to as "four-cornered" sails.
Square sails are square
Square sails are referred to as four-cornered sails.
"Square-riggers" have primarily square sails, but the jib sails are triangular.
"Four-cornered" sails were (are) square.
Well, back then people used the traditional square sails. So when the Caravel was built they used triangular sails instead of the traditional square sails which made the ship able to sail against the wind.
In the ancient world the square sail on "square rigged ships" was employed universally in the Mediterranean on the seagoing ships of the Egyptians, Phoenicians, Greeks and Romans. In Hellenistic and Roman times a spritsail (triangular sails) was sometimes set on a small raking foremast, known as an artemoon, in order to sail with a beam wind.
Square sails are referred to as four-cornered sails.