Measure the angles between two straight lines

[belgi]

Hello,
I just want to do a quite simple thing but actually I dont know how. I want to draw two straight lines in my picture and then measure the angles at the point where the lines cross.
It would be kind if someone helped me. I uploaded an example here.

[Dr. Busch]

Dear "belgi",

have you ever received an answer or found a solution for your problem?

Best wishes,
Heiner Busch