Introduction
Etymology: Latin word "angulus" which means a little bending
.
An angle is formed by two rays having the same endpoint called the vertex.
In geometry, an angle is measured in degrees; that is, the size of the angle.
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An angle can be named in three ways:
1) by the letter of the vertex
2) by the number or small letter in the angle's interior
3) by the letters of three points that form the angle
Task
At the end of this lesson, the students should be able to:
a) Differentiate the six kinds of angles.
b) Draw something that best represents him/herself with the different kinds of angles.
Process
In a blank sheet of a bond paper, draw any angle using the straightedge.
With the use of a protractor, measure the size of the angle.
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What kind of angle have you drawn?
Visit https://www.mathopenref.com/common/appletframe.html?applet=angleacute&wid=600&ht=300
and by dragging the orange dot, make an angle of the same size as what you've drawn on your paper.
.
Explore the different kinds of angles. You should be able to know all six kinds of angles.
.
Using different kinds of angles, draw something that best represents yourself at the back of the bond paper.
Also, explain in less than 5 sentences why does it represent you.
Evaluation
Score Card for Drawing:
| Content |
10 |
| Creativity and Originality |
10 |
| Overall impact |
5 |
| TOTAL |
25 points |
Conclusion
Kinds of Angles
|
Acute angle |
measures less than 90 degrees |
|
Right angle |
measures exactly 90 degrees |
|
Obtuse angle |
measures more than 90 degrees |
|
Straight angle |
measures exactly 180 degrees |
|
Reflex angle |
measures more than 180 degrees but less than 360 degrees |
|
Perigon |
measures exactly 360 degrees |
Credits
BUASEN, J. Course Manual in Plane Geometry. Benguet State University, La Trinidad, Benguet