How to calculate the center of a circle

1. If you know a circle, then make the perpendicular of two nonparallel strings, and the intersection of the two perpendicular lines is the center of the circle

2. Draw two line segments (strings) at will. The two line segments can't be parallel. It's better not to choose the diameter, and then make the middle perpendicular of the two line segments. The focus of the two middle perpendicular lines is the center of the circle
first draw a line intersecting with a circle, and the line segment in the circle is called a chord. Take the middle point of the chord as vertical to make a straight line, and then repeat the above steps (not the same line intersecting with the circle). The point where the two vertical lines intersect is the center of the circle
first measure the diameter or circumference of the circle to know the radius, and then use the length of the radius from any two points of the circle to intersect the end points of the lead wire, which is the center of the circle
fold the circle in half, the crease is the diameter, and the midpoint of the diameter is the center of the circle
or fold the circle twice, and the intersection of the creases formed by the two folds is the center of the circle.

3. Extend the 3 meter line and calculate the length of the extension line. No more questioning
take the middle position as the center of the circle

4. Simple
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5. Draw two right angles, the intersection of two hypotenuses

6. Find the standard equation of circle (x-a) (y-b) = R * r, then (a, b) is the center coordinates of the circle.

7.

The set of points in the plane whose distance from a fixed point is equal to the fixed length is called a circle. The fixed point is the center of the circle, as shown in Figure 1, and the fixed length is the radius of the circle

circle is a special kind of curve, which is not only an axisymmetric figure, but also a centrosymmetric figure. The straight line with any diameter of the circle is its axis of symmetry, and the center of the circle is its center of symmetry. Moreover, a circle can rotate at any angle around the center of the circle and coincide with the original figure

extended data:

center attribute

(1) the line segment connecting any two points on the circle is called chord, and the chord passing through the center is called diameter; The diameter is the largest string, and its length is twice the radius

(2) the distance between the chord and the center of the circle is called chord center distance

(3) the part between any two points on a circle is called an arc; The two ends of any diameter are divided into two arcs, and each arc is called a semicircle

(4) two circles with the same center and unequal radius are called concentric circles; Two circles with different centers and equal radii are called equal circles. In the same circle or equal circle, the arcs that can coincide with each other are called equal arcs. Equal arcs not only refer to the equal length of arcs, but also include the same degree of curvature of arcs. Therefore, there are no equal arcs in unequal circles

8. Let the center coordinates of two circles be (x, y) (m, n) respectively, and the distance formula between two points: D = √ [(x-m) + (y-n)]

9. If we say it's a ruler drawing
make a straight line randomly and cut a string by a circle
make the vertical bisector of the string to get a diameter of the circle
repeat to get another diameter
and then the center of the circle

10. Draw two line segments (strings) at will. The two line segments can't be parallel. It's better not to choose the diameter, and then make the middle perpendicular of the two line segments. The focus of the two middle perpendicular lines is the center of the circle.