Answer: 4.9 ft
Step-by-step explanation:
Given
Length of wire [tex]l=7\ ft[/tex]
Stake is at a distance of [tex]5\ ft[/tex] from the base of tree
suppose wire is attached y ft above the base of tree
from the figure, we can write
[tex]\Rightarrow 7^2=5^2+y^2\\\Rightarrow y^2=49-25\\\Rightarrow y=\sqrt{24}\\\Rightarrow y=4.89\approx 4.9\ ft[/tex]