Update Day_13.md

Author: darkprinx

Status/Day_13.md

@@ -66,6 +66,18 @@ print aRectangle.area()
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 **My Solution: Python 3**
 ```
+class Rectangle():
+ def __init__(self,l,w):
+ self.length = l
+ self.width = w
+
+ def area(self):
+ return self.length*self.width
+
+
+rect = Rectangle(2,4)
+print(rect.area())
+
 ```
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