Question

why great circles are short route for the poles​

Answer 1

Answer:

Why are great circles important in navigation? Because they show us the shortest routes between two points on a sphere. If we want to travel the shortest distance across any sphere, Earth being the obvious choice for most of us, you actually need to head towards the point on the opposite side of that sphere.

Answer 2

Planes travel along the shortest route in 3-dimensional space. This route is called a geodesic or great circle. While map projections distort these routes confusing passengers, the great circle path is the shortest path between two far locations. This is why pilots fly polar routes saving time and distance

Hope it will helps you☺