Circle Basics
1. A _____ is a segment with endpoints at the center and on the circle?
Radius
A ______ arc is the shorter of two arcs connecting two endpoints on a circle.
Minor
A _____ is a line in the same plane as a circle that intersects the circle in exactly one point, call the _______ ___ ________
Tangent, point of tangency
The _________ of a circle is the distance around the circle.
Circumference
A ______ is a segment with endpoints on the circle?
Chord
A ______ arc is the longer of two arcs connecting two endpoints on a circle.
Major
An _______ ____ has a vertex on a circle and sides that contain chords of the circle.
Inscribed Angle
A region of a circle bounded by a central angle and its intercepted major or minor arc is called what?
Sector
The radius formula for a circle is _______?
r=d/2 or r=1/2d
A _______ is an arc with endpoints that lie on a diameter.
Hint: The arc measure of every _______ is exactly 180 degrees.
A Semicircle
If two inscribed angles of a circle intercept the same arc or congruent arcs, then the inscribed angles are what?
Congruent
What is the formula for arc length?
S/ 2πr = θ/ 360
What is the formula for the diameter of a circle?
d=2r
Arcs in the same or congruent circles that have the same measure are called ________?
Congruent arcs
A _________ _________ is a line, ray, or segment that is tangent to two circles in the same plane.
Common tangent
What is the formula for Sector Area?
Sector Area/ Area of a circle = Measure of Arc/ measure of whole circle
Coplanar circles that share the same center are called _______?
Concentric
Arcs in a circle that have exactly one point in common are called _________ ____
Adjacent Arcs
If an angle is inscribed in a circle, then the measure of the angle equals what?
1/2 the measure of its intercepted arc.
What formula do you use to find sector area if the angle is given in radians?
A/ πr2 = θ/ 2πr