Geometry
Lesson
–
4th
Grade
 (Acute
Angle,
Right
Angle,
Obtuse
Angle)
 Trevor
Carrier
 
 Objective:

 
 a. Students
will
be
able
to
define
right
angles,
obtuse
angles
and
acute
angles.
 b. Students
will
be
able
to
draw
right
angles,
obtuse
angles
and
acute
angles.
 c. Students
will
be
able
to
physically
create
right
angles,
obtuse
angles
and
 acute
angles.

 Materials:
 
 1. Pattern
Blocks
 2. Toothpicks
(box)
 3. Glue
 4. Construction
Paper
 5. Pen/Pencil
 6. Angle
Worksheet
(Provided
by
the
teacher)

 7. Definitions
Worksheet
(Provided
by
the
teacher)
 
 Standard:


Understand
angle
 and
area
as
 Geometry
&
 measurable
 Measurement
 attributes
of
real‐ Compare
angles
according
to
size.
Classify
angles
as
acute,
 world
and
 right
and
obtuse.

 mathematical
 4.3.2.2
 
 objects.
Use
 For
example:
Compare
different
hockey
sticks
according
to
the
angle
 various
tools
to
 between
the
blade
and
the
shaft.
 measure
angles
 and
areas.



 Anticipatory
Set:

 
 Angles
are
a
very
important
concept
in
geometry
though
they
are
not
often
 thought
about
in
our
daily
lives.
However,
angles
impact
our
lives
in
more
ways
than
 we
think.
(Explain
to
students
that
we
all
use
angles
without
even
realizing.)

How
 angles
are
used
in
the
world
around
us?
Create
a
list
from
the
brainstorming
 session.
Ok
class,
now
lets
work
together
and
answer
some
more
questions.
 Remember
there
are
NO
bad
answers!
How
do
people
in
various
professions
use
 angles
to
complete
their
work?
(Let
students
respond)
How
do
all
people
use
angles
 in
their
everyday
lives?
(Let
students
respond)
How
do
you
use
angles?
(Let
 students
respond)

 
 Procedure:
 
 Pattern
Blocks
 
 1.
(Hand
out
the
definition
sheets
of
the
various
angles
to
the
students.)
Lets
start
 with
a
right
angle.
Look
at
your
worksheet
and
point
out
what
a
right
angle
looks
 like.
What
are
some
characteristics
that
you
notice
about
all
right
angles?
(Discuss
 student
responses)
A
right
angle
ALWAYS
measure
90
degrees
and
look
like
a
 perfect
corner.
Now
can
someone
point
out
what
an
acute
angle
looks
like?
What
are
 some
characteristics
that
you
see
in
the
acute
angle?”
(Discuss
student
responses)
 An
acute
angle
ALWAYS
measure
less
than
90
degrees.
So
remember
an
acute
angle
 is
less
than
the
90
degrees
angle.
Finally,
can
someone
point
out
the
obtuse
angle?
 What
characteristics
do
you
see
in
the
obtuse
angle?”
(Discuss
student
responses)
“
 An
obtuse
angle
ALWAYS
measure
more
than
90
degrees,
but
less
than
a
flat
line.”



2.
Using
the
handout,
have
the
children
read
over
the
definitions
out
loud
to
get
a
 further
grasp
of
the
subject
and
the
vocabulary
used.

 3.
Hand
out
the
pattern
blocks
to
the
students.
Remind
the
students
to
be
careful
 with
the
blocks
and
be
respectful
of
others
property.

 4.
Give
ample
time
for
the
students
to
examine
the
pattern
blocks
(a
few
minutes).
 5.
Have
the
students
look
at
the
pattern
blocks,
“find
the
ones
that
contain
right
 angles,
and
hold
them
up
in
the
air.”
(The
students
should
show
a
square,
or
right
 triangle
if
present)
Have
the
student
discuss
why
their
particular
block
is
a
right
 angle.

 6.
**
Stress
that
all
of
the
square's
angles
are
right
angles
equal
to
90
degrees
each
 and
that
some
geometric
shapes
will
have
right
angles,
but
that
all
of
the
angles
may
 not
be
right
angles.
 7.
Next,
“find
acute
angles
and
hold
those
in
the
air.”
(The
students
should
show
a
 triangle.)
Also,
remind
students
that
its
not
a
race
and
to
just
take
their
time
to
 formulate
the
correct
response.
Have
the
student
discuss
why
their
particular
block
 is
an
acute
angle.
 8.
Finally,
“can
you
find
an
obtuse
angle
and
hold
it
up
in
the
air.
(The
students
 should
show
an
octagon.)
Have
the
student
discuss
why
their
particular
block
is
an
 obtuse
angle.

 9.

“You
all
did
a
great
job
in
finding
the
correct
angles.
Does
anyone
have
any
 questions
before
we
continue
our
lesson?”
If,
no
have
the
students
pack
up
all
the
 pattern
blocks
and
put
them
away.

 
 Fun
With
Names
And
Toothpicks



 10.
Give
each
student
handful
of
toothpicks,
a
bottle
of
glue
and
a
sheet
of
 construction
paper.
Using
the
toothpicks,
the
students
should
spell
out
their
own
 first
name.
Once
the
names
are
spelled
out,
check
to
see
what
angles
are
properly
 formed.
The
students
should
glue
the
toothpicks
to
the
construction
paper,
clearly
 label
the
angles,
and
provide
a
definition
of
the
angles
underneath.
After
the
 students
have
completed
their
name,
review
their
individual
names
and
see
what
 angles
they
came
up
with.

 
 Worksheet
Time!
 
 11.
You
did
such
a
great
job!
Now
we
are
going
to
practice
all
that
we
have
learned
 today
with
a
quick
worksheet.

(Hand
out
the
worksheet)

 
 Closure:
 
 “Ok
boys
and
girls
what
are
some
things
you
learned
today?
(Have
each
 student
in
the
group
answer.)
It
was
a
fun
day
and
I
hope
you
remember
some
of
the
 techniques
we
learned
from
our
lesson
together,
I
need
everyone
to
pack
up
their
 stuff,
head
back
to
your
seats
and
I
will
see
you
next
time.”
 
 Informal
Assessment:

 
 Teacher
guided
questions
throughout
the
lesson
to
help
students
understand
what
 was
being
taught.
The
small
group
question
and
answer
at
the
beginning
of
the
 lesson
will
help
the
teacher
guide
the
students.

 
 Formal
Assessment:

 
 Today’s
formal
assessment
is
having
the
students
complete
the
final
worksheet.



 References:


 
 Parker,
Chonna
(n.d)
Angles.
Retrieved
March
23,
2010
from
Hot
Chalk
Lesson
Plans
 Page
Website:
 http://www.lessonplanspage.com/MathRightAcuteObtuseAngles6.htm