# Praxis II 0069 Geometry: Properties of Circles

## 23 terms · properties of circles

### circle

a set of points equidistance from the center

segment going from the center to any point of the circle

### chord

segment containing 2 points on the circle

### diameter

a chord passing through the center of the circle

### circumference

distance around the circle

### arc of a circle

is the set of points between and including two point on the circle

### semicircle

Half of a circle, degree of measure of a emicircle is 180 degress

### central angle of a circle

is an angle that has its vertix at the center of the circle, determines two arcs on a circle

### minor arc of a circle

smaller of two arcs - measured in degrees

### major arc of a circle

larger of two arcs - measured in degrees

### inscribed angle of a circle

vertix is on a cirlec and whose sides are chords of the circle

### intercepted arc of a circle

interior arc of an inscribed angle and whose endpoints are on the sides of the angle

### secant to a circle

line going through a circle, is a line that contains a chord

### tangent to a circle

line touching outside of circle, is a line in the plane of the circle that intersects the circle in only one point.

### concentric circles

are circles that have the ame center

### sector of circle

is region bounded by two radii and an arc of the circle

### polygon inscribed in a circle

if each of its vertices lies on the circle, polygon inside circle

### polygon is circumscribed about a circle

if each of its sides is tangent to the circle, circle inside polgyon

### point of tangency

the point of contact

### inscribed angle measure

is half the measure of intercepted arc

### intercepted arc measure

is twice the measure of the inscribed angle measure

### two intersected chords angles measure

each of the interior angles formed equals one-half the sum of its interrcepted arcs

### two intersected cords segment length

one chord equals the product of the lengths of the segments