Python core 55.2 tuples exercise

Question

Could someone explain the maths to me in the above exercise. I had to look up the solution and although the code makes sense I'm not grasping the equation.

Answer 1

It's nothing but geometry: We calculate the Euclidean distance between 2 coordinates using the Pythagoras theorem.

https://www.cliffsnotes.com/study-guides/geometry/coordinate-geometry/distance-formula