This example (using 3- 1/2" posts) gives you two choices.
One is with 8' panels.
The other is with 10' panels
The measurements are pulled off the inside corners of the posts.
Shortly, I'm sure someone will post to explain to you how to do a Pythagorean Theorem calculation. It's simple:
where
c represents the length of the
hypotenuse, and
a and
b represent the lengths of the other two sides.
In words:
The square of the hypotenuse of a right triangle is equal to the sum of the squares on the other two sides.
That's the way we were taught in school. In the field we shorten it to using three numbers that all carpenters memorize... 6, 8, 10. (And some guys use different numbers than other guys... perhaps, 3, 4, 5 or some other combination.)... it still works out to give you a 90 degree angle.
But this drawing will give you the numbers on a typical fence setup.