Geometry Chapter 10

circle

set of all points in a plane that are equidistant from a point called the center

center

the point that all points on a circle are equidistant to

radius

a line segment with one endpoint at the center of a circle or sphere and the other endpoint on the circle or sphere

chord

a line segment with endpoints on a circle

diameter

a line segment that passes through the center of a circle and has both endpoints on that circle

secant

a line in the plane of a circle that intersects the circle at two points

tangent

a line in the plane of a circle that intersects the circle at exactly one point

central angle

an angle whose vertex is the center of a circle and whose rays contain radii of the circle

minor arc

an arc having a measure less than 180 degrees

major arc

an arc having a measure greater than 180 degrees

semicircle

half of a circle; an arc that measures 180 degrees

inscribed

an angle whose vertex is on the circle and whose rays contain chords of the circle

intercepted

an arc on a circle whose points lie between the rays of a given angle

arc

an unbroken part of a circle

circumference

the distance around a circle

circumscribed

a circle that encompasses a polygon and passes through every vertex of that polygon

pi

an irrational number represented by the ratio of the circumference of a circle to the diameter of the circle

point of tangency

the point where a circle and a tangent intersect