Circles Flashcards
What is the theorem about right angles inscribed in a circle?
If a right triangle is inscribed in a circle, then the hypotenuse is a diameter of the circle.
What is the standard equation of a circle?
(x-h)^2 + (y-k)^2 = r^2
What is the theorem about tangent segments?
Tangent segments from a common external point are congruent.
What is the Arc Addition Postulate?
The measure of an arc formed by two adjacent arcs is the sum of the measures of the two arcs.
What is the theorem about diameters being perpendicular?
If a diameter of a circle is perpendicular to a chord, then the diameter bisects the chord and its arc.
What is the converse of the right triangle theorem?
If one side of an inscribed triangle is a diameter of the circle, then the triangle is a right triangle and the angle opposite the diameter is a right angle.
What is the Measure of an Inscribed Angle Theorem?
The measure of an inscribed angle is one half the measure of its intercepted arc.
What is the theorem about two inscribed angles?
If two inscribed angles of a circle intercept the same arc, then the angles are congruent.
What is the theorem about chords being a perpendicular bisector?
If one chord is a perpendicular bisector of another chord, then the first chord is a diameter.
What is the Angles Inside the Circle Theorem?
If two chords intersect inside circle, then the measure of each angle is one half the sum of the measure of the arcs intercepted by the angle and its vertical angle.
What is the theorem about tangent lines and radii?
In a plane, a line is tangent to a circle if the line is perpendicular to a radius of the circle at its endpoint on the circle.
What is the Segments of Secants Theorem?
If two secant segments share the same endpoint outside a circle, then the product of the lengths of one secant segment and its external segment equals the product of the length of the other secant segment and its external segment.
What is the theorem about minor arcs and chords?
In the same circle, or in congruent circles, two minor arcs are congruent if their corresponding chords are congruent.
What is the theorem about chords being congruent?
In the same circle, or in congruent circles, two chords are congruent if they are equidistant from the center.
What is the Quadratic Formula?
x = b+ or - √b^2-4ac
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