It is an arc
An arc is a portion of the circumference
An arc is a portion of the circumference of a circle.
circumference = 2*pi*radius or pi*diameter
An arc
The converse of the statement "If two circles have the same diameter, then they have the same circumference" is "If two circles have the same circumference, then they have the same diameter." This means that if you know two circles share identical circumferences, you can conclude that their diameters are also equal.
The circumference of a circle = pi*diametre = 2pi*radius
The equator.
Pi times the diameter of a circle gives its circumference.
The ratio of the circumference of a circle to its diameter is Pi. (3.14159)
Then they are similar.
A part of the circumference is called an arc. If the circumference is split into two unequal arcs then the larger portion is referred to as the major arc and the lesser portion as the minor arc.
Circumference is a special name for a circles perimeter. I think the answer you are looking for is radious.