Lesson-4.markdown

@@ -45,6 +45,14 @@ When placed on the left hand side of the black line the car successfully followe
 When placed on the right hand side of the black line the car turned once around itself before crossing the line, but without following it however.
 So in order for this application to work properly, the car had to start of the left hand side of the line. 
 
+### Exercise 3, ThreeColorSensor with Calibration
+
+### Exercise 4, Line Follower that stops in a goal zone
+
+### Exercise 5, PID Line Follower
+
+### Exercise 6, Color Sensor 
+
 
 ## Conclusion