Dividing a circle into 7 equal parts

How would I divide a circle into an odd number of equal parts (like 7)? I know I can keep inserting nodes but how do I make sure there’ll be 7 equal parts?

I might go about drawing a heptagon, a seven-sided polygon, centered inside an ellipse (circle), where the points of the heptagon are touching the circle. Then draw lines from each point to the center point of the circle. You will then have the locations to insert the nodes to divide the circle into 7 equal parts.

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(You geometric genius, you)
Beat me to it.

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Nice, I’ll try this method. Thank you!

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Hey Jim, just curious why the dimensions of you 7 sided object in the shapes property window do not match the width / height in the top left boxes?

Yeah, glad you noticed that. Others have mentioned that issue before and I stumbled upon it myself recently.
Oz gave a reason for it in another thread.
I just ignore the different numbers once I get the object like I want it. Maybe it will get sorted out at a later time.

Look at this thread and see if it helps make sense of what might be going on. Oz’s response is near the bottom.

Steve, thank you for that information.

Somehow I’ve have overcomplicated this problem to being unsolvable. I’m trying to cut shelves for my observatory. It’s diameter is 2185mm divided by 7 panels creating the circle. I want to cut 255mm wide shelves for each panel. I drew a 2185 mm circle (rear edge of shelf), a 1930mm circle (front edge if shelf), and the 7 sided shape then aligned all the centers. The attached picture is what I got. None of the lines have clear intersection points as I expected. I know I can drag, drop, and fudge them to make it work. However, I want to be able to cut pieces as needed (at different times) and not worry about the angles or measurements being off. Any help is appreciated.

Do you want the lines to be inscribed or circumscribed?

I need the 7 sided shape to go through the first circle and stop at the second (bigger) circle with an intersection point that I can manipulate.

Like this?

Close, but I need the inner and outer edges to be circular instead of flat. My observatory is a circle with no flat sides. I’m trying to make the shelves the same.

OK. Then check your math. You say the inner diameter is 1930mm and the outer diameter is 2185mm and the shelf is 255mm wide. When I subtract 1930mm from 2185mm and I divide by 2, I get a shelf width of 127.5mm - Assuming you want a 255mm shelf, one of the diameters needs to change

Something like this? I drew a circle 2185mm and one 1930mm. Drew a single line from the top of the outer circle to the top of the inner circle. Selected the line and outer circle then used the circle array to plot 7 lines.

Ralph,
Why are you dividing by 2? This may be what I’m missing.

Micro, this is what I’m trying to do. I’ll research the circle array as I’m not familiar with this method.

Ralph, this is a mistake I’m making. My goal is to have the shelf approx 10 inches (255ish mm)wide. So, the inside circle needs to be smaller. and, this image you uploaded is what I’m trying to do.

Math is off hold on

Inside diameter is 1675mm
2185mm-255mm-255mm
Shelf.lbrn (23.9 KB)

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