Answer:
17 feet
Step-by-step explanation:
To start, you can imagine the tree, it's shadow, and the distance between the tips to form a right triangle. Using the pythagorean theorem, you can find that that distance (the hypotenuse of this imaginary triangle) is [tex]\sqrt{15^2+8^2}=\sqrt{225+64}=\sqrt{289}=17[/tex] feet. Hope this helps!