Question 305996
I believe they mean the physical slide itself, that is the length of plastic
material that make up the slide is 400 yds long. That would make it
the slanted part or hypotenuse.
The vertical part is 36.3 yds
I'm not sure if the angle of depression is the angle the slide 
makes with the ground, or the angle it makes at the top with
the vertical.
If it's the angle the slide makes with the ground,
call that angle {{{a}}}
{{{sin(a) = 36.3/400}}}
{{{sin(a) =.09075
{{{a}}} = arcsin{{{.09075}}}
You can find this on your calculator