Why Are Televisions Rectangular in Shape?

I have never seen a round television monitor, but there is a good reason for this .

Television screens are optimized to show two dimensional (2D) images. A 2D image has X and Y coordinates. The dimension of X and Y coordinates can be represented as a rectangle. Any other shape would waste pixels when 2D images are shown.

The rectangular shape also closely aligns with a human’s field of view which is 180 degrees horizontal by 135 degrees vertical.

As 3D images become more common, there is a possibility that the shape of television screens may change .  If we can have a round watch, why can’t we have a round television monitor?