Calculate Included Angle of Axial lines

Discussion created by wangzhu102200 on Mar 4, 2013
Dear All,

I am doing a project work about using space syntax method to have an urban morphological study of city Beijing at geometrical perspective. I have generated axial map from street networks, but now I have a question to calculate the included angle (or maybe called turning angle) for thousands of intersection axial lines.

All my axial lines are polyline shapfile that had been saved into one layer, and I think this axial lines only have two vertexes for each one of them. Also, I have found the intersection points and the angles between axial lines and positive X-axis in ArcGIS 10. Could anyone teach me to calculate the included angle between two axial lines? I am much foolish, therefore, I wish to detail helping or step by step teaching. Thank a lot for your helping!

There is a screenshot to show which my data look like:

It is the first ring structure of city Beijing, and the red points are intersection parts of two axial lines.

Best Regards,
Have a nice day,