The exercise concerns measuring altitude of an observed point above the surface of the earth.
But you've already given the altitude of the observed object in your OP (5600 miles).
So, once more, what's the point?
The point is the title of the OP.
If you do not wish to answer the title of the OP, fine.
My answer is that your OP is very poorly presented.
Okay.
You present 1700 miles as the base of a right triangle.
Discerned that from a poorly written OP.
Then you present an observer with an unknown eye level 3 feet away from a 10 foot pole that is the very tip of that 1700 mile right triangle.
Eye level does not matter.
The height of the pole (10 feet) and the fact the top of the object is visible despite the pole is the only data in question.
I contend that you have not provided enough information to properly calcualte that the object in the sky is 5600 miles high.
Your contention is wrong.
The object, the top of the pole and the eye line of the observer must line up along the hypotenuse of the right triangle. You must either provide the height of the observer's eye level or completely remove the observer in order to make the problem solvable.
Wrong.
All that is necessary is for one to know the top of the pole still allows for the top of the sighted object to remain visible.
Where do you see or read or otherwise detect ridicule taking place here in this thread?
Well, right here, for one.
Go play with the cat clods in your sandbox.
That was written to you AFTER the post you made, repeating your meaningless off-topic and senseless objections to an OP you know provides correct math and a way for anyone to calculate the true altitude of the sun.
Now cease with the off-topic banter and pure, senseless objections to the OP.