發送短信

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

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發送短信 : A Mathematical App for the Conceptual Understanding of Area and Perimeter