IMPORTANT DEFINITIONS OF THE CIRCLES

CIRCLE
It is a geometry figure that has not side 

CIRCUNFERENCE
It is a closed curve line .The complete distance of the circle

CENTER
The center is the middel point of the circle or the circunference

RADIUS
Is the line to join the center of the circle whit one side

DIAMETER
Is the line that joinsa point of the circunference  whit another point of the circunference passing by the center

ARC
It is the line segment of a circle