math circles quiz

Chord

A line segment that has endpoints on the circle.

Diameter

is a chord that contains the center point of the circle

Radius

a line segment with one end point at the center of the circle and the other end point on the circle.

Central angle

an angle whoe vertex is at the center of a circle

Central Angle postulate

The measure of a central angle is equal to the measure of the arc that it intercepts

Arc addition postulate

The measure of an arc formed by 2 adjacent arcs is the sum of the measures of the 2 arcs.

Secant

a line that intersects a circle at two points.

Tangent

A line that intersects a circle at one point

Arc of the chord

When a Minor arc and a chord have the same endpoints, the arc is called the arc of the chord

Theorem 10.7

in a circle, if the diameter is perpendicular to the chord, then it bisects the chord and its arc.

Theorem 10.6

in a circle or in congruent circles, 2 minor arcs are congruent if and only if their corresponding chords are congruent.

theorem 10.9

In a circle or in congurent circles, 2 chords are congruent if and only if they are equidistant from the center

inscribed angle

an angle formed by two chords in a circle that share a common endpoint (the vertex) located on the circle's circumference.

Equation of a circle

(x-h)²+ (y-k)²=r²