<html><head></head><body><div class="yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div dir="ltr" data-setdir="false">Hi. I'm new to QGIS. I've been up all night reviewing the Training Manual and watching tutorial videos looking for someone to address my situation. I'm overtired and I'm sure I'm missing something obvious.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">I'm trying to create a large-format paper wall map to show all the roads in my county, and I have to create an atlas to do it.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">For sake of this question, let's assume the county is approximately 19 miles east-west and approximately 28 miles north-south. The key word here is approximately - and I suspect this task requires precision that I don't know how to find. </div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">All the lessons for creating grids from which the atlas will be generated instruct me to do it the same way: specify the desired horizontal and vertical intervals. That's not what I want.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">What I want is to divide the extent by three, whatever interval that happens to be. And I can't figure out precisely the total dimension, in miles, of the map extent. In case this is relevant: the data layers are projected in <span>NAD83 / North Carolina (ftUS) but the QGIS GUI at the bottom right says "Unknown CRS." </span></div><div dir="ltr" data-setdir="false"><span><br></span></div><div dir="ltr" data-setdir="false">I created a layer for this exercise - don't ask me to explain how I did it - whose only feature is a rectangle covering the area to be divided. This layer I call "Extent."</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">I try to use the Measure tool to get the exact east-west distance of the polygon. BUT. I have to manually select the start and end points, and I have no confidence that the points I'm selecting precisely match the limits of the polygon because when I measure the north and south horizontal lines, I get two different values. It's a rectangle. The values ought to be the same.</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Am I going bout this all wrong? How do I create this 3 x 3 grid?</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">Thanks - </div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">John A.</div></div></body></html>