Arc.
Ark is part of the circle's circumference.
Quadrant
Arc
if you mean the point that starts at the edge of the circle and ends in the center then this is the radius (:
Semi means part of. So semi circle is part of a circle.
it means it comes in shapes
Circumduction
Diameter, cord, radious.
Pendulum
open circle menas it is not part of the solution set and closed circle means that it is part of the solution
It means that the value represented by the circle is part of the solution set.
an open circle on a number line means the answer is just less than or greater than (< or >), but a closed circle means the answer is less than or equal to, or greater than or equal to (< or > with a line under it)