Circles Vocabulary
The distance from the center of a circle to any point on the circle
Radius
The space around the circle
Circumference
An angle whose vertex is located at the center of a circle
Central angle
An angle whose vertex lies on the circle and whose sides are chords
Inscribed angle
If an angle is formed on the inside of a circle, to find the measure of the angle, what operation do we perform
Addition
What is the standard form for the equation of the circle
(x-h)^2+(y-k)^2=r^2
A shape with four sides and four right angles
Rectangle
A line segment that connects two points on a circle but does not have to pass through the center
Chord
The space that covers the inside of the circle
Area
The sides of a central angle are called
Radii or 2 radius
If an inscribed angle intercepts an arc measuring 80 degrees, the angle measure is
40 degrees
If an angle is formed on the outside of a circle, to find the measure of the angle, what operation do we perform
Subtraction
In the equation,
(x-3)^2+(y+2)^2=25
what number represents the radius squared
25
The number that appears the most in a data set
Mode
A line that touches a circle at exactly one point
Tangent
A straight line has a measure of
180 degrees
The measure of a central angle is equal to the measure of its intercepted
Arc
All inscribed angles that intercept the same arc have this relationship
They are congruent
A secant intersects a circle at how many points
Two points
(h,k) represent what part of the circle?
Center
The force that pulls gravity towards Earth
Gravity
A line that intersects a circle at two different points
Secant
A circle measures how many degrees
360 degrees
If a central angle measures 65 degrees, the measure of the arc is
65 degrees
An inscribed angle that intercepts a semicircle always measures this
90 degrees
Whether angles are formed inside, outside, or on the circle, what do we always do to find the measure of the angle
Divide by 2
If
r^2=16
what is the radius of the circle?
4
The imaginary line that divides Earth into the Northern and Southern Hemispheres
Equator
A chord that passes through the center of the circle
Diameter
A piece of the circumference of a circle is called
Arc Length
A circle is divided into 6 congruent sections by central angles. Each central angle measures this many degrees
60 degrees
If an inscribed angle measures 35°, the intercepted arc must measure this
70 degrees
Angles formed inside the circle can be formed using
Chords and secants
Given this equation,
(x-4)^2+(y+1)^2=9
what is the center of the circle?
(4,-1)
What fraction represents one out of four equal parts?
1/4
Part of a circle formed between two points on the circle and measured in degrees
Arc
A "piece of the pie" of a circle is called
Area of the Sector
Two central angles intercept arcs of equal measure. The angles must have this relationship
They are congruent
Two different inscribed angles intercept a 100° arc. Each angle measure is this
50 degrees
Angles formed outside the circle can be formed using
Tangents and secants
Name the equation of a circle centered at the origin and has a radius of 7
x^2+y^2=49
What do we call an angle smaller than 90 degrees
Acute angle