I'll give you a hint: cut the cone along a straight line through the top to the bottom and smooth it. The straight line between two points is the shortest. ?

The answer is root number 20. Not two, three. I'm not qualified to illustrate.

You cut a cone from AB and AC to get a sector.

According to the original cone structure, BC arc length is 2? π? . So the side of sector ABC is 4 and the arc is 2π, so the angle A is a right angle. AB=4, AP=2 .BP is the hypotenuse and the root of 20.

It is said that it is two threes. Do you think cats can travel in space?