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

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