Introduction to Geometric Construction: Angles

Geometrical construction of lines involves the use of lines and angles to depict a shape or an object.



A Line is a mark or stroke long in proportion to its breadth, made with a pen, pencil, tool, etc on a surface. 

A line can also be defined as a long thin mark made by a pen, pencil, marker, etc. 


Types of angles: 

· Acute Angle: This is an angle less than 90º 


· Obtuse Angle: this angle is greater than 90º but not more than 180º 



· Reflex Angle: this angle is greater than 180º but not more than 360º 



· Right Angle: this is angle 90º 



· Angle on a straight line: the angle is 180º. It is also referred to as ‘straight angle’.



· Angle that makes a revolution: the angle is 360º or angle around a point. It is full rotation.



· Complementary angles are two angles with the sum of 90º 



· Supplementary angles are two angles with the sum of 180º 




Questions: 

1. What does geometrical construction of lines involve? 

2. What is a line? 

3. Outline and clearly describe 5 different types of angles. 

4. Outline the differences between acute, Obtuse and Reflex angles. 

5. Why is 180° called a straight angle? 

6. Differentiate between complimentary angles and supplementary angles.

Leave a Reply

Your email address will not be published. Required fields are marked *