Concentric Circles?
We call it a circle.
A circle with three dimensions is sphere.
Inscribed
To find the angle of a triangle within a circle segment, you first need to determine the central angle of the circle segment. Then, you can use the properties of triangles inscribed in circles to find the angle. The angle of the triangle within the circle segment will be half the measure of the central angle.
There are infinite diameters within a circle.
A quarter of a circle or a quadrant!
Eccentric circles.
If they share the same centre - they're 'concentric'
A. If the line segment touches two points on the circle it is called as: 1. secant; if the line extends outside the circle. 2. chord; if the line is present only within the circle. B. If the line segment touches one point on the circle AND the center of the circle AND is present only within the circle it is called as: radius.
A target
We call it a "semi-circle"
Within the circle
a circle within a circle within a circle decrealsing in size every time
A semi-circle
We call it a circle.
A section of the outside of a circle is called a "circular segment." It refers to the area enclosed by a chord and the arc that connects the endpoints of the chord. If you're referring to the area outside the circle but within a certain boundary, it could be referred to as the "exterior" or "surrounding area" of the circle.
The points in a circle are just points in a circle. Also, a plane cannot be within a circle because planes go on forever in all directions, so a circle can be within a plane.