added 6.3.8

Author: DirDraggo

CodeHS/6/3/8/Area-of-a-square-with-default-parameters-Travis.py

@@ -0,0 +1,10 @@
+def calculate_area(side_length = 10):
+    print side_length
+    print side_length * side_length
+
+user_length = int(input("Enter side length: "))
+
+if user_length <= 0:
+    calculate_area()
+else:
+    calculate_area(user_length)