Answer:
22.35 m
Explanation:
Hello , I can help you with this.
Step 1
define a right triangle
height of the three: H
opposite side=
the height of the tree - 1.8 m as the horizontal should be at the height of the guard's eyes
opposite side=
H-1.8
adjacent side=distance between the guard and the tree= 9.5 m
adjacent side= 9.5 m
Hypotenuse=distance between ranger's eyes and the top of the three=C
Hypotenuse=C
α=angle between the hypotenuse and the adjacent side =65.2°
α=65.2°
Step 2
find the value of the hypotenuse with the cosine function

put the values into the equation and solve for hypotenuse

Step 3
find the value of the opposite side using the Pythagorean theorem
T.P

solve for op.side and put the values into the equation

Step 4
use the equation opposite side=
H-1.8 to find H ( height of the three)
opposite side=
H-1.8
20.55=H-1.8
add 1.8 in both sides
20.55+1.8=H-1.8+1.8
H=22.35 m
Have a great day.