Drag drop shapes into canvas and make them resizeable

Question

Hi 

1) I want to build  a small project  in (asp.net webforms ) using visual studio 13 

2)  Actually i want to buil a small application which have a canvas area and some shapes like triangle, rectangle,  arrow  and lines to show  relationship between them.  

3) Like MS Visio software product.

4) End user can draw the diagrams as he want

5) But I am confused yet how to start and do.

 

kindly any one can help me about this what to do for this.

thanks for your consideration.