How to find the center of a circle

In the manufacture or processing of wood parts, in some cases it is necessary to determine where their geometric center is located. If the part has a square or rectangular shape, then this is not difficult to do. It is enough to connect the opposite corners with diagonals, which at the same time intersect exactly in the center of our figure.
For products that have the shape of a circle, this solution will not work, because they do not have angles, and therefore diagonals. In this case, some other approach based on different principles is needed.
And they exist, and in numerous variations. Some of them are quite complex and require several tools, others are easy to implement and to implement them you do not need a whole set of devices.
Now we’ll look at one of the easiest ways to find the center of a circle with just an ordinary ruler and pencil.

The sequence of finding the center of the circle:

1. To begin with, we need to remember that a chord is a straight line connecting two points of a circle and not passing through the center of the circle. It’s not difficult to reproduce it: you just need to put the ruler on the circle in any place so that it intersects the circle in two places and draw a straight line with a pencil. The segment inside the circle will be the chord.
In principle, you can do with one chord, but to increase the accuracy of establishing the center of the circle, we will draw at least a couple, and even better - 3, 4 or 5 different chords in length. This will allow us to level out the errors of our constructions and more accurately cope with the task.
2. Next, using the same ruler, we find the middle of the chords reproduced by us. For example, if the total length of one chord is 28 cm, then its center will be at a point that is located in a straight line from the intersection of the chord with a circle by 14 cm.
Having determined the centers of all the chords in this way, draw perpendicular lines through them, using, for example, a right triangle.
3. If we now continue these straight lines perpendicular to the chords towards the center of the circle, then they intersect at about one point, which will be the desired center of the circle.
4. Having established the location of the center of our particular circle, we can use this fact for various purposes. So, if you place the leg of a joiner's compass at this point, you can draw an ideal circle, and then cut the circle using the appropriate cutting tool and the center point of the circle that we defined.