Question 757456
A Pythagoras question.
Tree = x
Shadow = x - 17
Distance from top of tree
to end of shadow = x + 8
So x^2 + (x - 17)^2 = (x + 8)^2
  x^2 +(x^2 - 34x + 289) = (x^2 + 16x + 64)
 Combine and collect like terms.
       x^2 - 50x + 225
       (x - 5)(x - 45)
So either x = 5  or x = 45
As the shadow = (x - 17) I would
discount x = 5.
Tree height = 45ft
Tree's shadow = 28ft
Distance from top of
tree to tip of shadow.
= 53ft.
Hope this helps.
:-)