By the end of this activity students should be able to identify three types of angles, know that angles are measured in degrees, and be able to measure angles using protractors or angle rulers.
Additional Resources
Media
Prior knowledge needed to complete this activity: Be able to identify parallel, intersecting, and perpendicular lines. By the end of this activity students should be able to identify:
Right angle: A 90-degree angle
Acute angle: An angle that is less than 90 degrees
Obtuse angle: An angle that is greater than 90 degrees
Know that angles are measured in degrees and develop benchmark angles (e.g. 45 degrees, 60 degrees, 120 degrees) and be able to measure angles using protractors or angle rulers.
5. Connect mathematical ideas within mathematics, to other disciplines, and to
everyday experiences.
6. Represent mathematical ideas in a variety of ways.
Invitation to Learn
Divide class into two groups. Have them stand arm length apart in a circle. Give each group a ball of yarn. Instruct them to pass the yarn to make a web. They may not pass the yarn to the person next to them; encourage them to pass across the circle as much as possible. Each child needs to hold onto the yarn and not let go. When they are all holding onto the yarn have them carefully lay their web down on the ground, stretching it slightly so the yarn is in straight lines.
Review parallel, intersecting, and perpendicular lines by finding
them within the web. Have students identify the places where the lines
intersect and mark them with points. Explain that when two lines
meet together at one point we call that the VERTEX and that the lines,
which are called rays, extending from the vertex form an ANGLE.
Now look at the web to see if you can identify angles. Review how
lines are named by points. Explain that angles are named using
three points, with the vertex point always in the middle (ABC) and
that we use this symbol < for angle. ( Before the lesson prepare 12 angle cards. Use cardstock and draw
one angle on each card--make 4 right angles, 4 acute angles,
and 4 obtuse angles. Label the points and write the angle name
(example: Put students into small groups or partners. Give each group a
set of pattern blocks.
Tell them they need to look at each type of pattern block and
identify the types of angles on each. Give each student a piece
of art paper. Have them divide it into three sections labeled:
Right Angle, Obtuse Angle, and Acute Angle. Have them trace
the angles of the pattern blocks into the correct section.
Give each student a copy of the 360-degree Circle worksheet, which
has been copied on cardstock.
Discuss how a circle has 360 degrees. Link it to skateboard and
snowboard tricks like the 180 and the 360. As you discuss each
one have the students find it on their 360-degree Circle worksheet.
If you divide a circle in half how many degrees to you have?
180. Have them jump and spin and try to land at 180 degrees.
Now start at 0 degrees on your circle and trace your finger around
to 180 degrees. What about a half of the half? That would be 90
degrees. Jump 90 degrees at a time and see if they can figure
out the degrees--link it to the 9 times tables. So if you could
jump all the way around you would be doing a 360!
Have students put away their 360 degrees Circle paper so they cannot
see it during the following activity. Give each student a piece
of 9 x 12 art paper. Put students into partners and give each
group a set of fraction circles cut out of foam board. You need
to have a whole, halves, fourths, eighths, sixths, and thirds.
Have students fold their art paper to make four boxes. Have
them trace their whole circle in each of the boxes on the front
and in two boxes on the back. (Total of 6 boxes)
Work with students to identify the benchmark angles.
Begin with the whole circle. Review how many degrees are in a
complete circle. Write: "A whole circle has 360 degrees". Ask
how much of the circle 180 degrees would be. Have them find the
fraction pieces that would cover half the circle. In the second
box have the students trace the halves onto the circle, write
180 degrees on the circle in the correct place, trace the 180-degree angle in
crayon and shade it in. Above the circle write "180 degrees is
half the circle." (You can also teach your students that this is
called a straight angle)
Note: As you do these fraction pieces make sure they lay the
first fraction piece so its baseline is on the 0 degree line of the
circle, this will form the angle correctly.
Continue with 90 degrees. Remind them how far they had
to jump. How could you relate 90 degrees to a fraction of
your circle? Lay your fraction pieces on your circle and see
which ones correspond to 90 degrees on the circle. Find the
fractions that would make 90-degree angles. Trace the fourths,
highlight the first one-fourth, and label 90 degrees on the circle and
then above the circle write "90 degrees is 1/4 of the circle". As
you work through the rest of these angles have the students
compare them to the 90-degree angle to give them a reference point.
Repeat for 45 degrees, 60 degrees, and 120 degrees.
Draw a ray on each strip. Mark an endpoint on each ray,
then put the strips together to form a vertex and put the
fastener through them. Make a larger version for you to use
to demonstrate on the board. Have them look at their fraction
circle papers and try to reproduce the angles using their angle
manipulatives.
Show students an angle ruler and a protractor; explain that
these are the tools we use for measuring angles. Demonstrate
how they work. Put students into partners and let them
experiment with the tools. Draw different angles on the
overhead and measure them. Have students draw and measure
them with you. Have students use their angle manipulative.
Have them work in partners. One student will make an angle
using their manipulative; the other student will use the angle
ruler or the protractor to measure the angle.
Draw angles on the board or overhead. Have students estimate
and write down the angle's degrees. Then have students come
up and measure. If their estimate is exactly correct they get 10
points. Deduct one point for every degree they are off--if they
are one degree off they will get 9 points, continuing down to
9 degrees off they will get 1 point, 10 or more degrees off they
will get 0 points. Variation: Play STOP! Use a large angle manipulative on the board. Tape the bottom ray so that it stays
at 0 degrees. Identify the degree of angle you want to make. Choose
a student to come to the front. Their job is to yell, "STOP"
when they think you have made that degree of angle. They can
solicit help from the other students. Move the other ray slowly
(remember that angles are measured going counterclockwise)
The student yells stop when they think you have reached the
correct degree. Tape the ray down and measure the angle.
Choose your "winner" criteria before starting. Example: They
have to be within 5 degrees to win. If they win give them a
small treat.
Family Connections
Use the Angle Assessment blackline as a final assessment.
John Sutton, J., Krueger, A., (2002). EdThoughts: What We Know About Mathematics Teaching and Learning, (92).
Brain research demonstrates that: the more senses used in instruction, the better learners will be able to remember, retrieve, and connect the information in their memories. Physical experiences or meaningful contexts can provide learners with strong blocks for building knowledge. Providing our students with many different types of activities will help them learn the concepts or skills we are presenting.
Marzano, R.J., Pickering, D., & Pollack, J.S. (2001). Classroom Instruction that Works: research based strategies for increasing student achievement. ASCD, Alexandria, VA.
This text identifies instructional strategies most likely to lead to improved student learning. It looks at the research and theories behinds these strategies and gives suggestions for implementing in the classroom. One of the strategies discussed is kinesthetic activity that uses physical movement to generate an image of the knowledge in the learner's mind. Physically making things such as geometric shapes helps students connect terms and definitions to the actual things. Drawing pictures or symbols is also a powerful way to generate nonlinguistic representations in the mind.