Basic Terms for Circles Flashcards
What is a circle?
A circle is a set of points in a plane at a given distance (radius) from a given point (center) in that plane.
What are the parts of a circle?
What is a chord?
What is a secant?
What is the diameter?
Chord: a segment whose endpoints lie on a circle
Secant: a line that contains a chord
Diameter: a chord that contains the center of a line
What is a tangent?
A tangent is a line in the plane of a circle that intersects the circle in exactly on point called the point of tangency
What is a sphere?
A sphere with center O and radius r = the set of all points in space at a distance r from point O
What are congruent circles or spheres?
What are concentric circles?
Concentric circles (or spheres) are circles (or spheres) with congruent radii
Concentric circles are circles that lie in the same plane and have the same center (think of a bull’s eye)
