Circle Terminology

Circle Terminology - Transcript

GEOMETRY
Circle Terminology
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Radius (or Radii for plural)
• The segment joining
the center of a circle to
a point on the circle.
• Example: OA
O
A

Diameter
• A chord that passes
through the center of a
circle.
• Example: AB
O
A
B

Chord
• A segment joining two
points on a circle
• Example: AB
B
CA

Chord
• A segment joining two
points on a circle
• Example: AB
B
C
A

Secant
• A line that intersects
the circle at exactly
two points.
• Example: AB
D
C
B
A
O

Secant
• A line that intersects
the circle at exactly
two points.
• Example: AB
D
C
B
A
O

Tangent
• A line that intersects a
circle at exactly one
point.
• Example: AB
C
B
A

Central Angle
• An angle whose vertex
is at the center of a
circle.
• Example: Angle ABC
A
B
C

Inscribed Angle
• An angle whose vertex
is on a circle and
whose sides are
determined by two
chords.
• Example: Angle ABC
AB
C

Arc
• A figure consisting of
two points on a circle
and all the points on
the circle needed to
connect them by a
single path.
• Example: arc AB
A
B

Intercepted Arc
• An arc that lies in the
interior of an inscribed
angle.
• Example: arc AC
AB
C

Two Intercepted Arc
• If angle is inside the
circle.
• Example: arc AC
arc DF
B
F
A
D
C

• If angle is outside the
circle.
• Example: arc DE
arc DC
Two Intercepted Arc
E
D
B
A
C

Investigating Measures of Angles
Related to a Circle
• Click on GSP 4.00 on the desktop.
• Follow the instructions on the handout.