Comments by "Christian Baune" (@programaths) on "Math Queen" channel.

  1. Another way is to see that the line would sweep the same area if it rotates around itself or it's center. Same sweep, same area. A line rotating around make a circle with a radius of half it's length.
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  2. @ Swept area link to Cavalieri principle. Swept area is not an assumption and as strong as Pyhtagora ^^
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  3. The line would sweep the same area if it rotates around itself or it's center. Same sweep, same area. A line rotating around make a circle with a radius of half it's length.
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