Update Day_13.md

Author: darkprinx

Status/Day_13.md

@@ -1 +1,61 @@
 
+# Question 47
+### Level 1
+
+**Question:**
+
+***Define a class named Circle which can be constructed by a radius. The Circle class has a method which can compute the area. ***
+
+----------------------
+### Hints: Use def methodName(self) to define a method.
+-------------------
+
+**Main author's Solution: Python 2**
+```
+class Circle(object):
+ def __init__(self, r):
+ self.radius = r
+
+ def area(self):
+ return self.radius**2*3.14
+
+aCircle = Circle(2)
+print aCircle.area()
+```
+----------------
+**My Solution: Python 3**
+```
+```
+----------------
+
+# Question 48
+### Level 1
+
+**Question:**
+
+***Define a class named Rectangle which can be constructed by a length and width. The Rectangle class has a method which can compute the area. ***
+
+----------------------
+### Hints: Use def methodName(self) to define a method.
+-------------------
+
+**Main author's Solution: Python 2**
+```
+class Rectangle(object):
+ def __init__(self, l, w):
+ self.length = l
+ self.width = w
+
+ def area(self):
+ return self.length*self.width
+
+aRectangle = Rectangle(2,10)
+print aRectangle.area()
+
+```
+----------------
+**My Solution: Python 3**
+```
+```
+----------------
+