I was working through a problem the other day, and the approach I used led me to a point where I had to find the slant length. I thought that it would be easy, but I after thinking about it and attempting it, I realized I have no clue how to approach this. Any help would be greatly appreciated.

The height of this particular parallelogram is 3, while the top and bottom base are both 5. I am again, looking to find the sides d and b. Is there anyway to do this? Thanks!