"Square-riggers" have primarily square sails, but the jib sails are triangular.
caravel
A caravael
Square sails are square
Sloops, ketches, and yawls have triangular-shaped sails.
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
a ship with triangular sails that allowed it to sail into the wind and with square sails that carried it forward when the wind was at it's back.
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.
They were referred to as "four-cornered" sails.
A clipper.
Caravels are ships! They used triangular sails that, unlike traditional square sails, allowed ships to sail against the wind. By replacing oars on the ship's side with rudders at the back of the ship, the Portuguese also greatly improved steering.