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Posted: Tue Jul 04, 2006 10:59 am
by Shef01
Hi,

I need to work out the radius of an arc for a fenceline, what is the quickest or easiest way to do this? Great site by the way.

Posted: Sun Jul 09, 2006 3:12 pm
by Tony McC
Measure distance from point on arc to point of origin.

Posted: Sun Jul 09, 2006 3:53 pm
by bobhughes
How do I determine the radius of an arc?

Draw the arc to scale on paper (You could do it full size on the ground but you would need a very large pair of compasses

Take a pair of points on the arc. Open your compasses wide enough so two (equal) circles drawn with these points as centres will intersect.

Draw the two circles (or at least part of them) to determine their two points of intersection. Draw a line through the two points of intersection.
Take another pair of points on the arc and do the above construction again to draw another line the same way.
The point where the two lines you've drawn intersect is the centre of the circle your original arc belongs to. (And, of course, the distance between that centre and any point on the arc is the radius you were after.)

Or you can use the method describedhere