My first use of Mathematica is to draw a tree-graph. With few nodes it works. With many the labels are truncated. An example follows.

Can I widen the graph? Can I rotate it?

Here is the TreePlot:

list={"/proj/Test/dat"->"ABC.def","/proj/Test/dat"->"ABC.geo","/proj/Test/dat"->"ABC.inp",
"/proj/Test/dat"->"ABCExtractHist.inp","/proj/Test/dat"->"ABCHistory.dei",
"/proj/Test/dat"->"ABCln.DAT","/proj/Test/dat"->"ABCSeabed.dei",
"/proj/Test/dat"->"ABCXY.dat"}
TreePlot[list, VertexLabeling -> True (* , ImageSize -> 5 *) ]

Please forgive the bad reproduction of the lines. They are nicely formatted in a text editor running from the Windows command prompt --- apparently the system here do not recognize the end-of-line code.