# How to Precisely Position the Center of a Circle on a Board?

Thank you for taking my query.

I have drawn a board, 30"x15"x1". I want to draw small circles in precise locations on the board. So far I have learned that one cannot position the circle as one draws it–one must first draw the circle SOMEWHERE and then MOVE it to the desired location. I have successfully moved the circle to the desired location, but the move tool will not allow me to select the center point; it only allows me to select an endpoint that is located on the curve of the circle (or one of the endpoints among those formed by the straight edges that approximate the circle). This means that when I move the circle after selecting it (a point on the circle, not the center), that point that I have selected is placed at the coordinates I type into the move tool measurements box. So the center of the circle is off from the point I want it to be by the distance of the radius of the circle. Also, since the point on the circle I selected was imprecisely selected, it might be at any of the possible angles, making the positioning of the circle even less precise.

How do I move the circle so that the center of the circle is the same as the coordinates I want for that center point? Please assume my Sketchup ability is between 2.5 and 3.0 on a scale from 1 to 10. If at all possible, please describe how to do it entering endlessly precise coordinates in the Measurements Box. Thank you.

Let’s go back to the beginning. Why can’t you draw a circle in a precise location? At worst, create a couple of guides that cross at the required center, activate the circle tool, click at that crossing to place the center and drag out or type the radius. Much of the time you can get the center point by inference from other things such as edge midpoints without drawing the guides.

Let’s define a polygon. Poly means “many”. So, triangles on up. Squares, pentagons, hexagons and just keep going, circles included, as they are “polygons” as well. Any polygon drawn with the circle tool or the polygon tool has a feature to “find center”. This can be done (after creation) by hovering over the line, or a line in the polygon, either on a midpoint or a vertex, just for a moment. Sketchup should display the center of the polygon. After it does this, move your cursor to where that center was displayed. Your cursor will snap to that center (this is what’s known as inferencing) and from there you can move the polygon or rotate it or whatever you plan to do with it. Additionally, you can get sketchup to actually place a center marker in your polygon by right clicking and selecting “find center”. SU will place a marker with the characteristics of a guide point. When you view or hide guide points, or delete them, this marker will behave as all other guide points behave. It does not interfere with your geometry or interact with it, same as all other guide points. It just marks a point in space. If you plan to move your polygon and you wish the marker to go with it, you must also select it before you do the move. It’s a separate entity. Hope this helps.

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Not true. The most efficient method is to model the circle in the correct location initially using the inference engine to find the center of the rectangle. Hover (don’t click) over the midpoint of one side, then hover over the midpoint of an adjacent side, these two points are now stored in the inference engine memory, move toward the middle of the shape and the center inference will appear.

If you must move a circle, use the inference engine to pick it up by the center, and the same method to find the center of the rectangle you want to move it to.

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