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".
it is the square blade
The average size of a windmill blade ranges from 35 to 45 meters (115 to 148 feet) in length.
I don't think there is another name other than blade.
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.
vane
J.S Risdon inventeed it and in December 1872
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Technically, it is. Each blade is a lever, with the axle being the fulcrum of each lever.
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.
The average cost of windmill blades for a typical wind turbine installation is around 30,000 to 50,000 per blade.
Yes, a windmill typically has rotational symmetry because it looks the same when rotated around its central axis by certain angles. This is commonly seen in the blades of a windmill where each blade is identical and symmetrically arranged around the axis.