Question | Answer |
If a line through the center of a circle is perpendicular to a chord, | then it bisects the chord. |
If a line through the center of a circle bisects a chord that is not a diameter | then the line is perpendicular to the chord. |
If a line through a chord of a circle is the perpendicular bisector of the chord, | then the line passes through the center of the circle. |
Chord | A line segment with both endpoints on a circle |
Diameter | A chord that contains the center of a circle |
Arc | A portion of a circle |
Tangent | A line is tangent to a circle if it lies in the plane of the circle and touches the circle at exactly one point. |
Minor arc | an arc that is less than half of a circle |
Major arc | An arc that is more than half of a circle |
Semicircle | An arc that is exactly one half of a circle |
Central angle | an angle with its vertex at the center of the circle |
Reflex angle | An angle that is larger than 180 |
Equal chords of a circle have | equal arcs |
Equal arcs of a circle have | equal chords |
Inscribed angle | an angle with its vertex on a circle and its two sides intersecting the circle at two other points. |
The measure of an inscribed angle in a circle is | half the measure of its intercepted arc. |
If two inscribed angles intercept the same arc, | then the two angles are equal. |
If an angle is inscribed in a semicircle, | then it is a right angle. |
Secant | a line that intersects a circle (or other curve) in two points. |
Secant angle | An angle made from two secants |
The measure of a secant angle is related to | the measures of the arcs that the angle intercepts. |
Tangent line | touches the circle at one point |
Tangent segment | A segment of a tangent line with one of its endpoints on the circle |
The two tangent segments from a point outside a circle are | equal to each other |
The product of the lengths of the segments of one chord equals | the product of the lengths of the segments of the |