Geometry (Circles Part. 1) Flashcards
Circle
The locus of all points equidistant from a central point.
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Tangent
A straight line or plane that just touches a curve at one point.
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Secant
A line that intersects the curve in at least two (Distinct) points.
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Chord
A line segment connecting two points on a curve.
Minor Arc
An arc of a circle whose measure is less than 180°.
*Usually represented by only two letters “Arc (AB)”
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Major Arc
An arc of a circle whose measure is greater than 180°.
*Usually represented by three letters “Arc (ABC)”
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Radius
(Definition)
A straight line from the center to the circumference of a circle or sphere.
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Diameter
(Definition)
Any straight line segment that passes through the center of the circle and whose endpoints lie on the circle.
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Radius (From Diameter)
Equation
r = d/2
Diameter (From Radius)
Equation
d = 2r
The Diameter of a circle is 16 units.
What is the Radius of the circle?
r = (d)/2
r = (16)/2
r = 8
Radius = 8 Units
The Radius of a circle is 2 units.
What is the Diameter of the circle?
d = 2(r)
d = (2)2
d = 4
Diameter = 4 Units
What is the Radius and Diameter of the following circle?
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Radius = 8 ft
d = 2(r)
d = 2(8)
d = 16
Diameter = 16 ft
What is the Diameter and Radius of the following circle?
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Diameter = 12 in
r = (d)/2
r = 12/2
r = 6
Radius = 6 in
Circumference
(Definition)
The distance around a circle.
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