As you can see in the picture given in the exercise, the trapezoid can be divided into two figures: a rectangle and a Right triangle.
Let be "b" the base of the triangle (the horizontal distance indicated in the exercise). You can set up that:
[tex]\begin{gathered} b=36ft-28ft \\ b=8ft \end{gathered}[/tex]Now you can use the following Inverse trigonometric function to find the measure of the angle "x":
[tex]x=\sin ^{-1}(\frac{opposite}{hypotenuse})[/tex]In this case:
[tex]\begin{gathered} opposite=b=8 \\ hypotenuse=12 \end{gathered}[/tex]Then, substituting values and evaluating, you get:
[tex]\begin{gathered} x=\sin ^{-1}(\frac{8}{12}) \\ \\ x\approx41.8\degree \end{gathered}[/tex]The answer is:
[tex]x\approx41.8\degree[/tex]