Let x be the distance he steps back....so....
To find his original distance, d, from the tree we have
tan (68°) = 85/d
d = 85 / tan (68°) = 34.34 ft
So
tan (41°) = 85 / ( 34.34 + x)
(34.34 + x) = 85 /tan (41°)
34.34 + x = 97.78
x = 97.78 - 34.34 ≈ 63.44 ft
