Windmill sails Vane - Any of several usually relatively thin, rigid, flat, or sometimes curved surfaces radially mounted along an axis, as a blade in a turbine or a sail on a windmill, that is turned by or used to turn a fluid.
It's called "blade" or a "sail".
vane - Any of several usually relatively thin, rigid, flat, or sometimes curved surfaces radially mounted along an axis, as a blade in a turbine or a sail on a windmill, that is turned by or used to turn a fluid.
I don't think there is another name other than blade.
airplane shape flat on one side round on the other at 5 deg angle
it is the square blade
The average size of a windmill blade ranges from 35 to 45 meters (115 to 148 feet) in length.
The arm of a windmill is commonly referred to as a "blade" or "sail." These blades capture the wind's energy and convert it into rotational motion, which is then used to perform work, such as grinding grain or generating electricity. In traditional windmills, the blades are often referred to as sails, while in modern wind turbines, they are typically called blades.
flat
vane
J.S Risdon inventeed it and in December 1872
22/3