SOLUTION
Let us make a diagram to represent the information.
From the diagram above, we can see how the ladder made the angle 72 degrees elevation. This has made a right-triangle which can be seen at the right side. Using the right-triangle, we would be finding the side d.
From the trig-ratio SOHCAHTOA, we have that
[tex]\begin{gathered} SOHsin\theta=\frac{opposite}{hypotenuse} \\ CAHcos\theta=\frac{adjacent}{hypotenuse} \\ TOAtan\theta=\frac{opposite}{adjacent} \end{gathered}[/tex]From the right triangle I have made,
[tex]\begin{gathered} \theta\text{ means the acute angle 72}\degree \\ opposite\text{ is the side of the triangle opposite 72}\degree=27\text{ feet} \\ adjacent\text{ is the side that has the acute angle and 90}\degree,\text{ this is d} \end{gathered}[/tex]So we will make use of TOA, since the longest side which is hypotenuse is not given, so we have
[tex]\begin{gathered} TOAtan\theta=\frac{opposite}{adjacent} \\ tan72\degree=\frac{27}{d} \\ cross\text{ multiplying } \\ tan72\degree\times d=27 \\ tan72d=27 \\ dividing\text{ both sides by tan 27, we have } \\ d=\frac{27}{tan72\degree} \\ d=\frac{27}{3.07768} \\ d=8.77283 \\ d=8.8\text{ } \end{gathered}[/tex]Hence the answer is 8.8 feet to the nearest tenth