Tool to add triangular polygon

AlanTonkin

I have a road layout and at the road intersections I need to create what are termed "splays" in the Survey world. This is usually done by choosing the apex point and then creating a vertex a defined distance down each polygon edge running away from the apex point. The triangle is then created by joining the two new vertices with the apex vertex. I then need to merge this new triangular polygon with the adjoining polygon. See below:

And the end result being:

Is there a way to create a tool in ArcMap to achieve the above easily? Currently the method I am using is very cumbersome. Or has anyone already created such a tool?

Thanks in advance!

RebeccaStrauch__GISP

I would say yes this is very doable (but can't help right now).  I would do a search on either "arcpy split along line"  or split line at point, or some of the other terms similar.  Questions that would help others...

• Do you already know the apex (i.e. maybe separate point layer)
• are the distances the same for 1) each apex, 2) each line/direction

You should look at Geometry—Help | ArcGIS for Desktop    You can do just about anything in a python script with this, that is breaking any feature down to it's smallest part, basically an x/y coordinate. But someone may have already written something to I would look around on the web.

The "official" code sharing page from esri now is here: ArcGIS Code Sharing