From the given figure, we can see a right triangle of base 25 feet
An acute angle of measure 87.4 degrees
We need to find the opposite side to this angle, then we will use
tan (x) = opposite side/adjacent side
The opposite side is the height from the eyes of the student to the top of the Monument
The adjacent side is 25 feet
[tex]\because\tan (87.4)=\frac{h}{25}[/tex]Multiply both sides by 25 to find h
[tex]\begin{gathered} \therefore h=25\times\tan (87.4) \\ \therefore h=550.54275 \end{gathered}[/tex]Round it to 2 decimal places
∴ h = 550.54 feet
Add the height of the girl to it to find the height of the Monument
∴ The height of the Monument = 550.54 + 5 = 555.54 feet
∴ The tall of the monument is 555.54 feet