Constellation and Mathematics

Got out of the constellation Canis Minor. Winter Milky Way, the constellations in the east. In Greek mythology of Icarus King's faithful dog, the dog immediately named Myra.

According to Constellation, the distance between two points in a plane I remember.
Coordinate plane above two points and , the distance between

This formula uses the Pythagorean theorem, as shown in the picture above you will understand.