Circumference.
It is the name given to the straight line from the centre of a circle to its circumference when that distance is 28 cm.
It is the name given to the straight line from the centre of a circle to its circumference when that distance is 36 inches.
That's a radius of the circle.
There is no name given to it. (As the number of sides increases, the upper limit of a regular polygon is a circle.)
another name for a half circle is semi-circle
Circumference.
Circumference
the radius is half of the diameter
A small part of the distance around a circle is called an "arc." An arc is a segment of the circumference and can vary in length depending on the angle it subtends at the center of the circle.
It is the circle's circumference
circumference
the circumference
circumference
circumference
A circle.
Its name shall be called "circle".
That is called an "arc".