Here's another eg , all henges with an added astro phenomenon to boot.

Coupland – Balfarg = - 43.2465 .
Coupland – Moncrieffe = -43.1369
Balfarg – Moncrieffe = -43.5387 - 43.2465 .
Summer Solstice (sun set ) 2700bc = -43.29
which means tha tif you draw a line between Coupland hebge ,Balfarg henge and Moncriefee stone circle & henge it is accurate to within 0.1 degrees , at roughly the time the henges were the solstice setting sun was at the same bearing .