New test case proposal

I found a code during the random review that passed the test, but it certainly can't be good because I found a test case where the two triangles are not similar, but the function returns true.

https://py.checkio.org/mission/similar-triangles/publications/EvgenyS/python-3/why-not/

similar_triangles([(10, 10), (5, 10), (-10, -10)], [(10, 10), (7, 6), (-10, -10)])