Anyone any good with angles?

[Roadster99]

I ought to be able to work this one out myself but maths was never my best subject so here I am asking for help. I have to site my motorised 85cm dish on the north side of my house "looking" over the roof. My roof is angled at 35 degrees from the horizontal. The distance from the gutter to the apex in the horizontal plane is about 8 foot and about 5 foot in the vertical plane. My location latitude is 55.045.

My question is: How high above the gutter line will the base of the dish need to be to get the birds between 30 deg east and 30 deg west?

 

[georgia_grrl]

from my rough calculations 3 feet above shoudl cover it, though to be ont eh safe side i'd put it 3 and a half feet above the gutter. (i may be wrong as maths wasnt my best subject, but i was pretty good at it)

 

[Roadster99]

Thanks g g. I want to try and get it right first time. It would be easy to answer try it and see but atop a ladder above the roofline in not a place you want to be hanging around with a spanner or three.