Proportions by Leonardo da Vinci:
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        _-~                                 ~-_
    .--+--------------- ,  ,  , ---------------+--.
    |_/ E~c=-,         , ;'''; ,         ,-=5~3 \_|
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    +         /    /  f   fj  f   ;    \          +
    |~\      /  ,-'   ;   Y   |    ',   \       /~|
    |  \   ,' ,'      ',  |   ;      ~\  \____-/  |
    |   ~=[  f         ', |\  ;        ~\   _-~   |
    |      ~-L          | t | t          ]=~      |
    |         ~~--__    (  \(  ~-__ _--~~         |
    `---------------~~~-`---'------'--------------'