Circle Geometry Vocabulary
Arc Length
A fraction a a circle's circumference. The product of the ratio [measure of the arc]/360 and circumference
Perpendicular bisector
A line that cuts another line in half at right- angles to it.
secant
A line that intersects a a circle at two points (it contains a chord).
Segment of a Circle
A part of a circle bounded by an arc and the segment joining its endpoint.
Tangent
A straight line that touches the circle at a single point.
Inscribed Angle
An angle formed by two chords whose vertex lies on the circumference of the circle
Central Angle
An angle whose vertex is at the centre of a circle
central angle
An angle whose vertex is the center of the circle
major arc
An arc of a circle whose points are on or in the exterior of a central angle
minor arc
An arc of a circle whose points are on or in the interior of a central angle
Arc
Any section the circumference of a circle.
Radius
Any straight line from the center of a circle to its circumference.
Chord
Any straight line linking two points on a circle`s circumference, but not passing through its center.
semicircle
Half of a circle
Area
The amount of space inside a circle`s circumference.
point of tangency
The point where a circle and a tangent intersect
Circle
The set of all points equidistant from a given point called the center
circumference
The total length of the outside edge (perimeter) of a circle.
Congruent
To have the same size, shape, and measure.
sector
a region bounded by an arc of the circle
inscribed in a circle
all the sides of the polygon are tangent to the circle in the polygon.
intercepted arc
an arc whose endpoints are on the sides of an inscribed angle, and its other points in the interior of the angle.
Pythagorean Theorem
a²+b²=c²
inscribed quadrilateral
is any four sided figure whose vertices all lie on a circle.
Diameter
the distance measured from one point on a circle to another going through the center
