To solve this problem you must apply the proccedure shown below:
1- The ladder forms an isosceles triangle, because it has two equal sides.
2- Let's call the angle [tex] \alpha [/tex]. To calculate it , you can divide the triangle into two equal right triangles and the angle [tex] \alpha [/tex] will be divided into two equal parts too. Therefore, you can calculate the half of the angle and then multiply it by two, as following:
[tex] Sin^{-1}(\alpha 1)=opposite/hypotenuse [/tex]
[tex] Sin^{-1}(\alpha1)=8/2\\ \alpha1=14.47 degrees
[/tex]
[tex] \alpha =2\alpha 1\\ 2=2(14.47degrees)\\ \alpha =28.95degrees
[/tex]
The answer is: [tex] 28.95degrees [/tex]
