How do you find the radius of a circle?

Question

If you have a circle with no given information, how do you determine the center? Once I have the radius I know the formulas to figure out the restof the pertinent data.

Answer 1

me ges yu get a ruler or a tape meashyuer & tri tu hog-tie that dang serkel

Answer 2

Start at any point on the circle.

Draw a straight line to any other point on the circle.  This line is called a chord.

Measure the chord and find the middle of the chord.

Draw a line through the middle of the chord, but make that line perpendicular to the chord.

That new line goes through the center of the circle.

Measure the new line and find the middle of the new line.

The middle of the new line is the middle of the circle.