Answer: 25 ft.
Step-by-step explanation:
From the given picture, both man and tree are standing vertical to the ground.
Therefore, the angle that the sun hits the earth making shadows of both man and tree will be equal.
Thus, they will become similar triangles.
It gives that,
[tex]\frac{\text{height of tree}}{\text{length of shadow of tree}}=\frac{\text{height of man}}{\text{length of shadow of man}}\\\\\Rightarrow\ \frac{x}{40}=\frac{5}{8}\\\Rightarrow\ x=\frac{5\times40}{8}\\\Rightarrow x=25[/tex]
Hence, the height of tree is 25 ft.
