Kinds of Angles

LC: Visualize, name, and classify different kind of angles.

I. Learning Objectives: By using arm movements, pupils shall be able to:
C: classify angles as right, obtuse, acute, straight, or reflex.
C: identify the parts of the protractor.
P: demonstrate different kinds of angles using arm movements.
A: show enthusiasm by participating well in the activity.

II. Learning Content:
Topic: Kinds of Angles
Concept: Acute Angle – an angle that measures below 90 degrees.
Right Angle – an angle that measures exactly 90 degrees.
Obtuse Angle – an angle that measures more than 90 degrees but below 180 degrees.
Straight Angle – an angle that measures exactly 180 degrees.
Reflex Angle – an angle greater than 180 degrees.
Skill: Classifying Angles
Values: enthusiasm
Materials: model of different kinds of angles
Resources: Kotah, M. (2005), Soaring 21st Century
http://www.education.com/activity/fourth-grade/page7/
Glencoe, Mathematics Connection and Application

III. Learning Experience:
Classroom Routine - checking of attendance, ID, etc.
A. Introduction:
1. Prelection:
a. Review: Brainstorming (by pair)

With your protractor make a list of observations based on the physical appearance of the protractor.

The list may include the following:
- It is shaped like a semi circle (although some protractors can be a full circle)
- It looks like a ruler
- It has numbers labeled from 0 to 180
-There are two rows or scales of numbers
-The upper scale starts with 0 on the left side and increases to 180
on the right the lower scale starts with 180 on the left side
and decreases to 0 on the right
-The upper scale measures angles with openings on the left
- The lower scale measures angles with openings on the right
- The protractor is clear so that the angle can be seen and measured
accurately

2. Preview:
a. Motivation:
· Who can draw a picture of an angle on the board?
· Can you define it by your own words?
· What the word angle sounds like? Hint: Its part of your body.
· Explain that word angle comes from the word ankle, and that your foot makes
an angle with your leg.

b. Presentation of the day’s lesson

B. Interaction:
Activity 1: By pair
1. Measure students' angles. Show the students how to make an angle with your arms. Have one student in a group and have his right arm up level to his shoulder. Use a protractor to measure the angle.


· What did you notice on the position of the angle?
· What kind of angle is this?
· Can you identify right angles in the classroom?
2. Ask the student to put his arm a little bit down. This is an acute angle.

· What happens to the opening of the angle?
· What would happen to the measurement of the angle? Would it go up higher
or lower?
· What kind of angle is this?
3. Ask anyone to make an angle more than 90 degrees using their arms.

· What did you notice on the opening of the angle?
· What kind of angle is this?

4. Let the students figure out how 180 degrees would look like. Hint: Let them
realize that the measure of the two right angles is 180 degrees.


Activity 2: Drill
Teacher will give an angle measurement and students will demonstrate
through arms movements.

C. Integration:
1. Generalization: Journal-Writing
· What are the different types of angles?
· How do we measure angles?

2. Valuing:
· How do you find the activity today?

3. Action: List down a real life situation where you could use your knowledge
about angles.


IV. Evaluation: Fixing the Skills
Answer page 343 letter E – F.

A. Fill in each blank with the correct answers to complete the sentence.

1. A right angle has a measure of ______.
2. A straight angle has a measure of ____.
3. An acute angle measures between ____ and ____.
4. An obtuse angle measures between ____ and ____.

B. Classify each angle as acute, right, obtuse, or straight. (see page 115 of your book)



V. Assignment:
Invent a cheer utilizing arm movements that demonstrate the different kinds of angles. This will be performed on Monday.

Criteria:
Concept Accuracy: 20 points
Creativity: 20 points
Props/Costume 10 points