definition
A circle is the set of points equidistant from a given point called the center.   (The degree measure of an entire circle about the center is 360º.)
Notation for circle: circlenotation

radiusa

* Radii in a circle are congruent (of the same length).

chord

diameter
* A diameter is the longest possible chord.

Given circle O:
Warmupcircle
Arc:   arc a part of a circle's circumference.

Semicircle:   semi
- an arc whose length is exactly half of the circumference (with a corresponding central angle equal to 180º).

Central angles: ∠AOC, ∠DOC, ∠AOJ, ∠DOJ, ∠AOD, ∠COJ
- an angle whose vertex is at the center of the circle and whose rays (sides) are radii.


divider


NOTE: The re-posting of materials (in part or whole) from this site to the Internet is copyright violation
 and is not considered "fair use" for educators. Please read the "Terms of Use".