a rope dancer was walking on a loose rope tied to the top of two equal post of height 9m. when he was 3m above the ground, it was found that stretched pieces of roop made angle of 30 degree and 60 degree with the horizontal line parallel to the ground. find the length of the rope.

Answer 1

Unless you give the problem a different interpretation, Arora gave you a solution back here:
https://www.jiskha.com/display.cgi?id=1516706057

Did you look at it? What don't you agree with?

It said" a loose rope". By that I understood, as did Arora, that the rope is not straight across but sags.