They were referred to as "four-cornered" sails.
"Square-riggers" have primarily square sails, but the jib sails are triangular.
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.
The Cutty Sark had a total of 29 sails. Its sail plan featured a combination of square sails on the main and fore masts, along with fore-and-aft sails on the mizzen mast. This design allowed for efficient sailing and maneuverability, particularly in varying wind conditions. The ship was designed as a clipper, emphasizing speed and performance during its voyages.
Hispaniola is the ship he sails to Treasure Island
Lateen sails were adapted from the Mediterranean region.
They are referred to as four-cornered sails.
"Four-cornered".
Square sails are square
I don't think there is another name other than blade.
Square sails are referred to as four-cornered sails.
Trapezoidal, actually. But the square sails were called square sails. Lateen or square could be referred to as yards.
"Square-riggers" have primarily square sails, but the jib sails are triangular.
"Square sails" which are not really square, were/are referred to as four-cornered sails.
"Four-cornered" sails were (are) square.
Square sails (rectangular) were (are) called four-cornered sails.
Square sails are referred to as four-cornered sails.
Historically, they are referred to as "four-cornered" sails.