Answer:
ok so i really shouldnt get points for this, but i wanted to help. The person who solved the problem here: https://math.stackexchange.com/questions/2911546/suppose-the-sides-of-a-triangle-form-a-geometric-progression-with-common-ratio-r is correct, but it is not very clear. Basically, he rounded to the third decimal point (since a sqrt has infinate decimals), and this might have been what got you the wrong answer. Basically the important thing is that r has to be between the (-1+√5)/2 and (1+√5)/2, or (-1+√5)/2 < r < (-1+√5)/2
