The ladder reach up to 11.6 ft on the wall.
To solve this, we use trigonometry. We have a hypotenuse of 12ft, and we want to know the lenght of the leg opposite to the angle of 75º. The trigonometric function that relate all 3, is sine:
[tex]\begin{gathered} \sin \theta=\frac{opposite\text{ leg}}{adjacent\text{ leg}} \\ \end{gathered}[/tex]
Using the numbers of the problem, and h is the leg we want to find:
[tex]\begin{gathered} \sin 75º=\frac{h}{12ft} \\ h=\sin 75º\cdot12ft\approx11.6ft \end{gathered}[/tex]
Then the top of the ladder is at 11.6ft from the floor