Goal: Students will be able to identify, draw and measure angles
(ODE, 2007, Math, 4th grade GAP Standards)
3.3 Geometry and Measurement: Describe and Analyze Properties of Two-Dimensional Shapes, Including Perimeters
3.3.1 Identify right angles in two-dimensional shapes and determine if angles are greater than or less than a right angle (obtuse and acute)
Lesson Topic: Classifying Angles as Acute, Obtuse, Right, Straight and Reflex. Practicing using a half-circle protractor for angle measurements
Content Objective: Given the necessary materials, students will be able to distinguish angle types and apply information by modeling correct use of a half-circle protractor to measure and draw angles with a minimum level 3 on grading criteria
Language Objective: Students will be able to:
Demonstrate proper use of a half-circle protractor
Read and understand the degrees of an angle
Measure and draw angles less than 360 degrees
Show comfort categorizing angles by type (acute, obtuse, reflex, straight, right)
Grading Criteria / Assessment Plan:
5: Student is an active listener during reading of “The Greedy Triangle”. Student shows attention through eye contact, body language or active participation during introduction to lesson. Student shows full participation during small group project. Student completes assigned angle measurements with >90% accuracy.
3: Student is a somewhat active listener during reading of “The Greedy Triangle”. Student shows some attention through eye contact, body language or active participation during introduction to lesson. Student shows some participation during small group project. Student attempts to complete assigned angle measurements with >70% accuracy.
1: Student is somewhat distracted during reading of “The Greedy Triangle”. Student shows minimal attention through eye contact, body language or active participation during introduction to lesson. Student was present without full participation during small group project. Student shows little to no attempt to complete assigned angle measurements.
Method of Instruction:
Angle, Side (of angle), Vertex (of angle), Rotation, Protractor, Circular, Half-Circle, Right Angle, Acute Angle, Obtuse Angle, Reflex Angle, Straight Angle, Base Line
Large Paper for Posters
Art Supplies (scissors, glue, crayons, pens)
Anticipatory Set (10 minutes):
Read “The Greedy Triangle”
CFU: “What are some things you learned from this story about angles?”
“Was any of the information about angles new to you? What?”
“Is this book helpful in terms of looking at angles in relation to triangles? We
Have only looked so far at circles, but angles are in all shapes!”
Stated Purpose (5 minutes):
“Today we are going to continue on our angle measuring journey! We are going to explore the half-circle protractor. You will each work on a team poster project. After we complete our group projects, your group will act as the teacher and teach us everything about your angle. We will end our lesson with complements about each other’s poster projects. There will be time for discussion about angles.”
CFU: “Who would like to demonstrate how to use a half-circle protractor?”
“How does a half-circle protractor compare to a circular protractor?”
Model (10 minutes):
First step will be to discuss the half-circle protractor and compare it to the circular protractor. Show how to use it to measure a few angles as example. When students entered room after recess they picked up a name tag. The name tags are cut into different angles. Have them stand around the room where they can observe each other’s name tags and see if they can figure out what the significance of each is. Tags will all be cut at different angles, but goal will be to have 4 max tags per group (acute, obtuse, reflex, straight, and right). One group of students will have full 360 degree tags and they will make up the “angle” group. They will be responsible for covering anything related to angles (what are they? Include vertex info, rays or lines, different types, etc.). Each group will get together and make a poster about their angle. The posters should have any information that we need to know about their angle. It’s up to the teams to include any necessary information and to design their posters. Be sure to set a timer for teams with 5 minute warning on time allowance.
CFU: “Are there any questions?”
“How will team work look for this activity?”
Guided Practice (25 minutes):
While students are working in small groups I will walk around asking and answering engaging questions. I will observe how teams are working together to accomplish this task.
Closure (10 minutes):
Understanding angles and how to measure them is going to be a great accomplishment from this point on in mathematics. We will continue to measure and discuss different angles this week, so please make sure you ask questions if you are not sure of what we are doing.
CFU: “With quiet hands, who has a complement they would like to share about one
of the posters?”
“Was this project helpful? Was if fun!?”
“Did you learn more about angles?”
Adaptations / Extensions:
Adaptations: Pair students who may struggle with concepts with students who can assist with learning process.
Extensions: Have students make a list of angle measurements throughout the classroom using half-circle protractors