Thread: how can i find this difficults geometric relations for dislocations ?

Hello world

i work on dislocation and i try to find several geometric relations with the figure which is bellow:

Geometricproblem.jpg

to help me i know this :

explication.jpg

i know that for a squarre distribution a particules my length is :



my questions:
- can you help me too find all this relations ?
- if i consider a triangular network for this particules all this relations are always good ?

thanks for your help !!!

ps: my english is not very nice, sorry