15 Replies Latest reply on Mar 4, 2011 11:02 AM by dlee-esristaff

    How do I create a 2 acre square?

    linb001
      My boss asked me to create a 2 acre square. Is there an easy way to do this? I calculated the number of square meters in an acre, took the square root of that and drew two lines at right angles using Direction/distance (started line then did rt click to access Direction/Distance tool). I then used the rectangle tool in Advanced editing (using the shift key to draw a square) and snapped to the lines I created. This worked but theres gotta be a better way to create a square of a given size.
        • Re: How do I create a 2 acre square?
          johns
          You could have used that tool to create one more vertex and then hit the F2 key to finish, or you could use the square and finish option on a right click.

          You could alternately create a graphic square and in the properties enter the appropriate length and width.  If needed then convert that to a shapefile.  For one that is rather clumsy compared to the prior but for many copy and pastes of it it might be okay.
          • Re: How do I create a 2 acre square?
            keags1
            Ok, this might work for you.

            Does your site have a centroid?
            If not create one.

            Using the buffer tool, buffer the point by half of length you want the polygon to be.
            I work with the metric system, but the idea should be the same.
            So if I want a 100m^2 square, I would buffer the point by 5m.

            Once the buffering is complete, you have a circle around the centroid. The diameter of this circle equals the width of your square.
            You then need to (using ET Geowizards, downloadable for limited free use from (http://www.et-st.com/downloads/etgw/ETGeoWizards99_92.zip I recommend this tool if you dont already have it).

            Ok so using ET go to the "Misc" Tab and locate the "Features to Envelope" tool, select it, then your buffer layer and choose an output.

            You should now have a square to your exact specification, without having to measure and worry about editing graphics.

            I hope that helps.
            • Re: How do I create a 2 acre square?
              falltroy
              All these options sound like they work just fine but seem complicated and time consuming. Should'nt there be an easier way to create a simple square specifiying the desired amount of acreage, sq feet, ect.
              • Re: How do I create a 2 acre square?
                keags1
                Oh you wanted somethng quick and easy, why didnt you say so :p

                First you need to download another nice little tool called Hawth's Tools, even if you dont want to use it for this task it has a few nice tools that can make life very easy
                .
                http://www.spatialecology.com/htools/download.php
                Designed by: Hawthorne Beyer
                email: hawthorne@spatialecology.com

                Once you have it installed, make sure you have your centroid point(s) set up over your site.
                Next open up Hawth's Tool, Select the Sampling Tools Menu and then the "Create Sample Plots (Various Shapes)" Tool.
                Select your centroid as the input, you want a square shape so leave that, then for dimensions, select half the diameter of you desired square.
                Once again I am metric so if I wanted a 100m^2 plot I would choose 50 as the dimension.
                Select your output directory and run the tool.

                That is the easiest, quickest method I can think of.
                • Re: How do I create a 2 acre square?
                  falltroy
                  Now that is more like it:):):D That is very easy. Still I would think that would be a built in function of ArcMap. Oh well maybe in v10.
                  • Re: How do I create a 2 acre square?
                    goh_raj
                    You should post this idea to:  http://ideas.arcgis.com/
                    I'd vote for it.
                    • Re: How do I create a 2 acre square?
                      cfdirt
                      FISHNET!!!!!!!!!!!!!!! (With an ArcInfo license)
                      • Re: How do I create a 2 acre square?
                        keags1
                        Fishnet is a good idea.
                        Just unfortunately not everyone has ArcInfo / X-Tools Licenses.

                        I am also not sure if the fishnet allows for a central point to be used a starting location, and thus the defined area square may not fall over a chosen site.

                        Unfortunatley I don't have access to either of these to test it. :)
                        • Re: How do I create a 2 acre square?
                          gbarden
                          If you know the width and length of the square your trying to draw, draw a square using the graphic tools. Open the properties for the graphic and on the Size and Position Tab you can type in the values for height and width. Once you Apply these values, you can check the area on the Area Tab.

                          If you need the square to be a feature, use the Convert Graphics to Feature on the Graphics Tool Bar.

                          Gary Barden
                          1 of 1 people found this helpful
                          • Re: How do I create a 2 acre square?
                            linb001
                            Thanks so much for all the response. Looks like ya gotta do some sorta song and dance just to make a simple square of a given area (2 acres in my case) regardless of how you approach it. I assumed I was missing the "click here and enter your dimintion" button. Seems like a pretty basic kinda function.
                            • Re: How do I create a 2 acre square?
                              dlee-esristaff
                              Following the step of creating a buffer with a buffer distance = half of the side of the square, you can then use the Feature Envelope To Polygon tool in ArcToolbox - Data Management - Features toolset to obtain the envelope of the buffer. This envelope should be the square you want. This tool requires an ArcInfo license.
                              • Re: How do I create a 2 acre square?
                                recurvata
                                A square acre is 660 feet per side, so for two acres 1320. You could just draw a line that long, take the same length at 90 degrees, back 90 @ 1320 feet, then 90 back to origin. This doesn't take centroid into account, but should draw the square pretty simply.
                                • Re: How do I create a 2 acre square?
                                  mstead
                                  The editing tools in 10 are way better for this type of thing with the perpendicular/parallel tools, but your could always do this.

                                  Start editing your polygon layer, add a vertex, hit ctrl 'g' and type in a cardinal bearing (or whatever you want) and a distance (sqrt of area), hit ctrl 'g' and type in your initial bearing plus 90 degrees and the same distance, etc

                                  If you are generating this from centroids of an existing layer all this buffer/envelope stuff would be a good route as there is no need to manually create stuff. If you are just whipping up some squares to move where you want then this would be way easier. It's the same distance direction tool you initially started using. Not sure why you used it to create lines.
                                  • Re: How do I create a 2 acre square?
                                    recurvata
                                    With all due respect, I had googled the dimensions of a square acre and the length of a side is 208.71 ft.


                                    Yep you are correct, I was wrong. An acre can be defined as 660 by 66 feet (1 furlong by one chain), but obviously that's not a square. My bad.
                                    • Re: How do I create a 2 acre square?
                                      dlee-esristaff
                                      I was wrong.  The squares I created are dynamic until I convert them to graphics for placement in my legend.  I'll just hold off on that until my map scale is finalized. And... I used the 'Multi Ring Buffer' tool to create three sizes at once, and the 'Feature Envelope to Polygon' tool created the squares all at one time.  That in itself is a huge time saver.

                                      I probably should explain that I'm creating a scale "box" showing the relationship between 1, 5 and 20 acres.  Once the squares are created with the "Envelope" tool, I'm using Editor to align the squares at their upper left hand corner.  I created a field in the attributes table for acre size, then I used Maplex to place those labels where I wanted them to be.

                                      It's all working out very nicely, and I'll be using this method for four other maps.



                                      I am gald it all worked out for you.

                                      Thanks.