Circle: A set of all points in a plane placed at the same distant from a given point, named center.

Circumference: The distance around the circle.

Chord: A chord is a segment whose endpoints lie on the circle.

Coefficient: The numerical factors in a term.

Common factor: A number, polynomial, or quantity that divides two or more numbers or algebraic expressions evenly.

Commutative Law of Addition: a + b = b + a

Commutative Law of Multiplication: a x b = b x a

Complementary Angles: Two angles whose sum is 90 degree.

Composite Number: A natural number greater than one that is not a prime.

Congruent Figures: Figures that coincide, of fit, on another.

Counting Numbers: The set {1, 2, 3 …}

Constant: A term that has no variable factor.

Cube: A rectangular solid in which all the faces are equal.