We can clearly see the graph of an ellipse ‘e’ in red with the equation ((x-l)/a)^2 +((y-m)/b)^2 =1. If we change the values of a, b, l and m using their corresponding slide bars we will see that the shape, size and position of the ellipse gets changed. Let us observe how the size and shape of an ellipse changes as we change the values of a, b, l and m.

Questions to think about
1. Compare the coordinates of the center ‘A’ with l and m, what do you observe?
2. Find the lengths of straight lines BC and DE and compare them with a and b, what do you observe?
3. What do you observe when a = b?