How do i find the exact center of a circle without having the perimeter or area. I can use any tool.?

Question

HOw would i find the center point of a circle with just having the circle as reference?

Answer 1

I have done this many times.

1. Draw a line that is tangent to the outside of the diameter.
Measure the line and find the middle.
Draw a perpendicular line Through the circle.

2. Draw a second line that is tangent to the out side of the Diameter.
Measure the line and find the middle.
Draw a perpendicular line Through the circle.
Make the second line at least 90 degrees from the first line.

The intersection of the two lines inside the circle is the exact center of the circle.

Answer 2

Thales theorem of circles states "that if A, B and C are points on a circle where the line AC is a diameter of the circle, then the angle ABC is a right angle."

You can do just the opposite. Take a square (right angle tool) and place the right angled corner anywhere on the circle and draw lines out to where they intersect the circle (see the diagram) and you will have a diameter. Do the same at another point and where the diameters cross will be the center.

http://i35.photobucket.com/albums/d194/mekaniker/fun/CircleCenter2.gif

Answer 3

hi, What you flow with is define a set S(n) which calculate the exterior of a on a on an universal basis foundation polygon with n factors with a set perimeter P. S(0), S(a million) and S(2) have not got any meaning. S(3) would desire to be the exterior of a equilateral triangle. S(3) = (P/3) × P(?3)/2 = P²(?3)/6 S(4) = (P/4)² = P²/sixteen I shall come again anon... ;-)

Answer 4

Or draw any one line through the circle. Draw the perpendicular bisector of the first line. The halfway point of the 2nd line is the center.

Answer 5

Balance the circle on a pin.

Answer 6

Draw any two cords. Then find the intersection of their perpendicular bisectors.