23 terms

SindlingerTEACHER

Circle

ellipse in which the two axes are of equal length

Center

a point equidistant from the ends of a line or the extremities of a figure

Radius

the length of a line segment between the center and circumference of a circle or sphere

Diameter

the length of a straight line passing through the center of a circle and connecting two points on the circumference

Chord

a straight line connecting two points on a curve

Secant

a straight line that intersects a curve at two or more points

Tangent

a straight line or plane that touches a curve or curved surface at a point but does not intersect it at that point

Point of Tangency

the point where a circle and a tangent intersect

Central Angle

an angle whose vertex is the center of the circle

Inscribed Angle

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

Arc length

a portion of the circumference of a circle

Arc measure

the degree measure of an arc, found by measuring the central angle

Circumference

the length of the closed curve of a circle

Area of a circle

A=πr²

Area of a sector

A sector is a piece of the area of a circle. If n is the degree measure of the sector's central angle then the formula is: Area of a Sector = (n/360) (πr)2

In terms of Pi

3.14

Intercepted arc

the arc that lies in the interior of an inscribed angle and has endpoints on the angle.

Inscribed

a circle (on the inside) of a polygon and only touches each side at exactly 1 point

Congruent

Having the same size and shape

Concentric

arcs and circles that share the same center points

Cyclic

occurring or moving in cycles

Degree

A unit used to measure distances around a circle. One degree equals 1/360 of a full circle.

Semicircle

a plane figure with the shape of half a circle