Ch 10 Quiz Flashcards
measure of an arc
the number of degrees it occupies in a cirle. Since circles are 360, an arc is atmost 360
Length of an arc
The fraction of the circle’s circumference occupied by the arc; expressed in linear units such as feet centimeters or inches.
sector
The region of a circle created by a central angle.
how to find Arc Length and Sector measure
are proportional to each other and the central angle/360
Inscribed Angle
An angle formed by two chords whose vertex is on the circle, it is equal to half the arc it creates.
Distance from a chord to the center
The distance from the center of a circle to the chord is the measure of the perpendicular segment from the center to the chord
Theorem 1 and converse
If two chords are equidistant from the center then the two chords are congruent
If two chords are congruent, then they are equidistant from the center
congruent Arcs
Arcs with the same measure AND are parts of the same circle or congruent circles
Super theorem
Congruent cords means congruent arcs means congruent central angles means
Postulates
A Tangent line is perpendicular to the radius drawn to the point of tangency
If a line is perpendicular to the radius at its point of contact with the circle then the line is a tangent
Two tangent theorem
If two tangent segments are drawn to a circle from an external point then those segments are congruent
Tangent circles
Circles that intersect at exactly one point
commonn tangents
A line that intersects two circles at exactly one point each(internal and external)
Distance Between two circles
The distance between two circles lies along the line connecting their centers
area and circumference`
A=pi r^2
C=2r pi
