INSCRIBED ANGLES
and INTERCEPTED
ARCS
Learning Objectives:
• Define and illustrate
inscribed angles.
• Determine the relationship
between an inscribed
angle and its intercepted
arc.
• Find measures of inscribed
angles.
INSCRIBED ANGLE
An inscribed angle
is an angle whose
vertex lies on the
circle and whose
sides are chords of
a circle.
Not IA Not IA
IA IA
INSCRIBED ANGLE
A
Illustrative Examples:
B
C
O
Inscribed
Angle
∠ 𝑨𝑩𝑪
Intercepted
Arc
^
𝑨𝑪
A
Illustrative Examples:
B
C
O
Formul
a:
m
If = 140°, what is the
m?
m
m) = 70
A
Illustrative Examples:
B
C
O
Formul
a:
𝒎 ^
𝑨𝑪=2m ∠ 𝑨𝑩𝑪
If m = 75°, what is
the ?
𝒎 ^
𝑨𝑪 = 2 m ∠ 𝑨𝑩𝑪
𝒎 ^
𝑨𝑪 = 2(𝟕𝟓)=𝟏𝟓𝟎 °
A. Name all the inscribed
angles and their
corresponding intercepted
arcs.
CLASS ACTIVITY
Inscribed Angle Intercepted Arcs
Alternate Segment
Theorem
The angle between a
tangent and a chord at the
point of contact is equal to
the angle subtended by the
chord in the opposite
segment
of the circle
Circle Theorem's
Perpendicular Tangent
A tangent to a circle is
perpendicular to the radius at
the point of contact
Circle Theorem's
Two Tangent Theorem
Two tangents drawn
from an external point
are equal in length
Circle Theorem's
Chord of a circle
The perpendicular
bisector of a chord goes
through the center of a
circle
Circle Theorem's
Thank you for
listening!

Inscribed Angles and Intercepted Arcs.pptx