CC57126: Fixing minimun Value in get_Sides method

Hello, @mikeblome,

This proposed file change comes from https://github.com/MicrosoftDocs/cpp-docs.zh-cn/pull/14/files?utf8=%E2%9C%93&diff=split&w=1 . 
Line MicrosoftDocs#52

Could you review this contribution and help to merge if agreed?

Many thanks in advance.

Author: Gonzalo-Salines

docs/atl/adding-a-property-to-the-control-atl-tutorial-part-3.md

@@ -49,7 +49,7 @@ ms.workload: ["cplusplus"]
 
      [!code-cpp[NVC_ATL_Windowing#46](../atl/codesnippet/cpp/adding-a-property-to-the-control-atl-tutorial-part-3_3.cpp)]  
 
- The `get_Sides` method returns the current value of the `Sides` property through the `pVal` pointer. In the `put_Sides` method, the code ensures the user is setting the `Sides` property to an acceptable value. The minimum must be 2, and because an array of points will be used for each side, 100 is a reasonable limit for a maximum value.  
+ The `get_Sides` method returns the current value of the `Sides` property through the `pVal` pointer. In the `put_Sides` method, the code ensures the user is setting the `Sides` property to an acceptable value. The minimum must be 3, and because an array of points will be used for each side, 100 is a reasonable limit for a maximum value.  
 
  You now have a property called `Sides`. In the next step, you will change the drawing code to use it.