diff --git a/Tutorials/T04-A2Example/src/TriangleADT.py b/Tutorials/T04-A2Example/src/TriangleADT.py
index 75e8a17b89f407d68773c4adfb58ce15050feb24..44dbcb8ddcdcb9375baeaf764c7206fb75b8448b 100644
--- a/Tutorials/T04-A2Example/src/TriangleADT.py
+++ b/Tutorials/T04-A2Example/src/TriangleADT.py
@@ -24,16 +24,16 @@ class Triangle:
     #  @return The sides of the triangle
     def sides(self):
         seq = [0,0,0]
-        seq[0] = self.__a.dist(self.__b)
-        seq[1] = self.__a.dist(self.__c)
-        seq[2] = self.__b.dist(self.__c)
+        self.seq[0] = self.__a.dist(self.__b)
+        self.seq[1] = self.__a.dist(self.__c)
+        self.seq[2] = self.__b.dist(self.__c)
         return seq;
 
     ## @brief Inequality theorem
     #  @return the existence of a triangle
     def inequality_theorem(self):
         seq = self.sides()
-        if (seq[0] +seq[1] > seq[2] and seq[0]+seq[2] > seq[1] and seq[1]+seq[2] >seq[1]):
+        if (self.seq[0] +self.seq[1] > self.seq[2] and self.seq[0]+self.seq[2] > self.seq[1] and self.seq[1]+self.seq[2] >self.seq[1]):
             return True;
         elif (self.__a.xcoord()==self.__b.xcoord()==self.__c.xcoord() or self.__a.ycoord()==self.__b.ycoord()==self.__c.ycoord()):
             return False;
@@ -45,7 +45,7 @@ class Triangle:
     def perimeter_of_triangle(self):
         seq = self.sides()
         if self.inequality_theorem():
-            return seq[0]+seq[1]+seq[2]
+            return self.seq[0]+self.seq[1]+self.seq[2]
         else:
             print("You can't have a triangle with the points")
 
@@ -54,8 +54,8 @@ class Triangle:
     def area_of_triangle(self):
         seq = self.sides()
         if self.inequality_theorem():
-            P = (seq[0]+seq[1]+seq[2])/2
-            return sqrt(P*(P-self.seq[0])*(P-seq[1])*(P-seq[2]))
+            P = (self.seq[0]+self.seq[1]+self.seq[2])/2
+            return sqrt(P*(P-self.seq[0])*(P-self.seq[1])*(P-self.seq[2]))
         else:
             print("You can't have a triangle with the points")