Question

why we say hello when we call somebody

Answer 1

To continue from friends relationship and respecting to say hello to frnds .

Answer 2

Hi kanay

Telephone was discovered by Alexander graham bell his wife name is hello. He used to speak to her wife naming her as hello.
But all thought that was the way to speak first in telephone.Slowly this became habituated.

Though he is dead we all remember his wife hello.
Hope this help u friend