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

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