Definition and basic elements of a circumference
Indicate, in response to the description provided, which element of the circle is:
$C$: segment that connects any two points on the circumference.
$r$: segment that connects the center with any point of the circumference.
$o$: point in the plane which is at the same distance from all points of the circumference.
$D$: the largest string that exists in a circumference.
$S$: line that cuts any two points of the circumference.
The elements of the figure are the following ones:
$C$ is a string, an element that connects any two points on the circumference.
$r$ is the radius of the circle.
$O$ is the center of the circle.
$D$ is the diameter of the circle, the longest chord.
$S$ is a secant line to the circumference.
$C$: string, $r$: radius, $O$: center, $D$: diameter, $S$: secant line.