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