How to measure the center of a circle (just a plain circle with nothing in it)?

Question

Uuh, homework problem. I know there's a formula, but I don't know it yet. I have just a plain circle (and i could measure anything I want, radius, circumference). Help?

I'm in grade 7, so like give me some simpler terms. Like whats with the cords and stuff? Draw any 2 cords? Starting from where and to where?

I'm in grade 8, so like give me some simpler terms. Like whats with the cords and stuff? Draw any 2 cords? Starting from where and to where?

Answer 1

draw any two chords
draw their perpendicular bisectors
their point of intersection will give the center of the circle

Answer 2

You draw a square with all four sides tangent to that circle. Bisect the angles opposite each other. Figure out the hypotenuse of the isosceles triangle and divide it by 2.
That's 2 times the square of one of the equal sides: the product of which you take the square of. Half of that gets you the center.

Answer 3

draw two arbitrary different cords. Draw perpendicular bisector on each cord. The intersection is the center.

Answer 4

The formula of a circle is as follows:

(x-h)^2 + (y-k)^2 = r^2

Where x and y are the coordinates of the edge of the circle, (h,k) are the x and y coordinates of the centre of the circle, and r is the radius of the circle.

Answer 5

2 pie r