# Creating fishnet grid with specified rotation angle in ArcGIS Desktop?

I'm working on this project and I need a grid with a certain rotation, at about 60 degrees, for example.

Starting from that I need to make a block of 20mx50m, and the last thing is that inside each block there must be a small set of sub-blocks.

The result is this:

Of course it's been done manually, but I was thinking of a way of making it done automatically because I must do 30 blocks like this one, maybe more, and it is consuming a lot of my time.

• Please embed images inside the question, vice linking, so that the screenshot is less likely to disappear over time. Sep 22, 2014 at 19:05
• Create Fishnet (Data Managment) will create a polygon feature class, but you're on your own for sub-blocks help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//… Sep 22, 2014 at 19:06
• Look again at the `Y_axis_coord` parameter. It defines the orientation of the fishnet. Sep 22, 2014 at 19:34
• In order to set an angle, you need to do a little math as explained on the How Create Fishnet Works page. The angle is set using the line that connects the origin to the entered y-axis coordinate. Also, rather than working in with your grid you might try working out - create the smallest grid first, then use a Dissolve, Aggregate Polygons, or even copy and merge to create your larger grids. Sep 22, 2014 at 19:39
• @ChrisW I think you should write that up as the answer. I had not seen that part of the documentation and it is quite explicit.
– PolyGeo
Sep 22, 2014 at 22:27

The example given on the how it works page uses the math formula `tan (angle) = x coord / y coord`. However, if you don't want to do the math or need to set your origin at a different point than the CRS origin, there's a step to take prior to starting the fishnet tool to get your y-axis coordinate. Create a line feature snapping and clicking once at the desired point for the origin to start the line, then right-click and choose Direction. Enter the angle you want (note how this is entered may vary with how your Editor Options are set regarding Units, specifically angles, and the negative value thing above come into play here as well), drag out to lengthen the line and then click or F2 to finish it. You can then get the x,y of the endpoint or any point on the line and use that x,y as your y axis coordinate in the fishnet tool. You'll also have to note the x,y of the point you want to use as your origin to enter those coordinates, since the tool doesn't allow for click input.