Find which signal was transferred in 32QAM
Here's a sample 32QAM constellation.  With the scaling you were given, there's dots at every possible combination of $\lbrace -5 ... +5\rbrace$ except for the four at $(\pm 5, \pm 5)$.  &quot;Minimum Euclidean distance&quot; means that you find the dot that's closest to your actual received value and say that's the one -- i.e., if you receive $(-2.5, 1.2)$, then the nearest dot to that is $(-3, 1)$ and that's the one you decide on.
Just do that for the three I/Q pairs you've been given.  For extra credit, write a Python script...