We are led through this exercise 1 by clicking the "Questionmark Button" in the toolbar. Doing this we get additional hints as well as new questions and answers prepared by the teacher in the exercise console.
Alternatively, we can use the tool buttons and go through the exercise by ourselves.
We will get some information, comments and new questions in the exercise console as well.

The result of this exercise is the following:
The two WALLACE-lines of diametrically opposite points X and Y on the circumcircle of a triangle are perpendicular and the intersection point of these lines lies on the NINE-POINT circle. For the NINE-POINT-circle the teacher can prepare a hyperlink to more details.