Describir: Part4: Architecture of Form, variations un tube structure

  _  _    __   __              ______   __   __    _____     _  _     _____   
 | \| ||  \ \\/ //   ____     /_   _//  \ \\/ //  |  ___||  | \| ||  |  ___|| 
 |  ' ||   \ ` //   |    \\    -| ||-    \   //   | ||__    |  ' ||  | ||__   
 | .  ||    | ||    | [] ||    _| ||_    / . \\   | ||__    | .  ||  | ||__   
 |_|\_||    |_||    |  __//   /_____//  /_//\_\\  |_____||  |_|\_||  |_____|| 
 `-` -`     `-`'    |_|`-`    `-----`   `-`  --`  `-----`   `-` -`   `-----`  
                    `-`