# Finding coordinates of tangent points and intersection of curved line? [closed]

I have a line with curves in it.

Is there an easy way to extract the X Y values for the tangent points and intersection points in ArcMap 10.2.1?

Hopefully my simple paint diagram clarifies what I mean.

Fortunately I only have 1 line with about 8 of these rounded corners. I am going to create a new layer and draw in the straight lines leading up to the curve - snapping to the vertices but leave out the rounded corner. I will then extend the lines by whatever distance makes them all intersect and use that to give me the intersection coords. I can get the tangent ones easily enough. (My curves were originally just a lot of small connected straight lines but I have already manually edited them to arcs and simplified the vertices on straight sections - at most the line has moved 5m from the original which is fine for my uses).

## closed as too broad by PolyGeo♦, Paul, Simbamangu, Fezter♦, Alexandre NetoApr 6 '14 at 9:43

Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

• This question is more complicated than might appear. Any automatic solution would need to (a) identify segments of the feature that are perfectly linear and (b) are separated by portions whose curvature does not change sign and then (c) compute and output the intersections of their tangents. That's three operations; the first two are not native to most GIS platforms (including ArcGIS, I believe, although more is added to it regularly). Plan on writing code. – whuber Jan 31 '14 at 15:58
• I suggest that you move your edit as a possible answer to your question – radouxju Jan 31 '14 at 19:34
• As indicated by @whuber the solution would appear to need three questions answered in order to accomplish what you seek to do. Consequently, I recommend that you edit your Question to focus it on the first of those to which you do not already know the answer, and then research ask any remaining questions separately. – PolyGeo Apr 6 '14 at 4:26