Talk:Tienstra formula

Unclear

This article is unclear as the variables in the equation are undefined. A diagram would be nice to help define the quantities involved. WikiDan61^ChatMe!_ReadMe!! 20:42, 12 December 2013 (UTC)

E and N are Easting and Northing, meters east and north of a datum (corner of a UTM grid, or a local coordinate system like state-plane).

Angle "A" is the angle between lines to points B and C at point A - the internal angle at vertex A of triangle ABC. Angle alpha is the angle between lines to points B and C at the unknown point - the internal angle at vertex P of triangle PBC.

The other angles are defined similarly.

It's slightly different if the unknown point is not located inside triangle ABC, but the same principles apply, just one of the 'greek' angles will be an exterior angle instead of an interior angle.

Revent (talk) 04:33, 27 April 2014 (UTC)

Diagram required

Would benefit greatly from a diagram of the problem, showing all pertinent angles. --Haruth (talk) 22:56, 21 February 2015 (UTC)