Sophia Brahe was a Danish astronomer in the 16th and 17th century who worked with her brother Tycho Brahe, also astronomer, in the creation of a star catalogue that Kepler used as a source to find the laws on the movement of planets in the Solar System. She made the observations on the lunar eclipse of December 1573.

In this context we propose you to solve the following geometry problem:

Looking up at the sky, we notice ten stars in the following position:

Draw eight different triangles with their vertex in some of those nine stars. Classify the triangles obtained.