Download Chapter 1 Vocabulary Angles

Chapter
1
Vocabulary
Angles
Circumference
Concave
Polygon
Diameter
Two
rays
at
the
same
endpoint
The
perimeter
of
a
circle.
Formula:
C = D! A
polygon
with
1
or
more
interior
angles
greater
than
180 ° The
cross
section
of
a
circle,
it
cuts
the
circle
in
half.
Its
biggest
chord.
Line
Symmetry
A
polygon
has
line
symmetry
if
you
can
fold
it
in
half
along
a
line
so
that
the
two
halves
match
exactly.
Perimeter
The
distance
around
a
two‐dimensional
shape.
Regular
Polygon
A
polygon
with
sides
that
are
all
the
same
length
and
angles
that
are
all
the
same
size.
Perpendicular
Two
lines
that
cross
and
create
90 ° angles.
Polygon
A
shape
with
straight
lines
that
don’t
cross,
has
no
curves
and
has
vertices.
Radius
Half
of
a
diameter.
Right
Angle
An
angle
that
is
90 ° .
Acute
Angle
An
angle
that
measures
between
0 ° and
90 ° .
Obtuse
Angle
An
angle
that
measures
between
90 ° and
180 ° .
Protractor
A
tool
for
measuring
angles.
Intersecting
Two
lines
that
cross
each
other.
Lines
Vertical
Angles
When
two
lines
cross,
two
angles
not
next
to
each
other
are
vertical
angles.
Complimentary
Two
angles
that
add
up
to
90 ° .
Angles
Supplementary
Two
angles
that
add
up
to
180 ° .
Angles
Formula
Geometric
rule
that
uses
symbols
to
complete
a
task.
Chord
A
segment
connecting
two
points
on
a
circle.