Let C F subtend an angle y.
"Canadian Eclipse Party 1869"
Commander E. D. Ashe
The brighter parts of this nebula as seen from the earth subtend an angle of about half a degree, and while we know nothing of its distance from us, it is easy to see that the farther it is away the greater must be its real dimensions, and that this increase of bulk and mass with increasing distance will just compensate the diminishing intensity of gravity at great distances, so that for a given angular diameter-e.
"A Text-Book of Astronomy"
George C. Comstock
The meridian circle is indeed capable of such precision as a sighting instrument that it could be pointed separately to each of two stars which subtend at the eye an angle no greater than that subtended by an adjoining pair of the sixty minute dots around the circumference of a watch-dial a mile distant from the observer.
"The Story of the Heavens"
Robert Stawell Ball