Chapter 10: Circles Flashcards
Secant
Line that intersects circle at 2 points.
Chord
Line segment with 2 end points on a circle.
Tangent
Line that intersects a circle at one point.
Tangent segments from a common…
Tangent segments from a common external endpoint are congruent.
The radius of a circle is perpendicular…
The radius of a circle is perpendicular to tangent at point of tangency.
In the same circle or congruent circles, minor arcs are….
In the same circle or congruent circles, minor arcs are congruent iff their corresponding chords are congruent.
If one chord is the perpendicular bisector…
If one chord is the perpendicular bisector of another chord, then the first chord is the diameter.
If the diameter of a circle is perpendicular…
If the diameter of a circle is perpendicular to a chord, then its diameter bisects the chord and its arc.
In the same circle or congruent circles, 2 chords are congruent…
In the same circle or congruent circles, 2 chords are congruent iff they are equidistant from the center.
If two chords intercept inside a circle, then the product of the lengths…
If two chords intercept inside a circle, then the product of the lengths of the segments of one chord is equal to the product of the lengths of the second chord.
Segment of Secants Theorem
If 2 secant segments share the same endpoint outside the circle, then the product of one secant segment and its external segment are equal to the product of the lengths of the other secant segment and its external segment.
If a secant segment and a tangent segment…
If a secant segment and a tangent segment have a common endpoint, then the products of the length of the secant segment and its external segment are equal to the square of the lengths of the tangent segment.
Formula for graphing a circle whose center is at the origin
r2= x2+y2
Formula for graphing circles whose centers are not at the origin
r2= (x-h)2+(y-k)2
The measure of an inscribed angle…
The measure of an inscribed angle is half the measure of the intercepted arc.
