Angles ( Definition, types and measures of angles)
Class: Basic 5
Subject: Mathematics
Topic: Angles ( Definition, types and measures of angles)
An angle is a point where two or more lines meet each other.
The unit for measuring angles is degree. A protractor is used in measuring and drawing angles.
Types of angles
1.) Acute angles: These are angles less than 90°. Examples are 21°, 45°, 60°, 78°, 83°, etc.
2.) Obtuse angles: These are angles greater than 90° but less than 180°. Examples are 95°, 110°, 127°, 169°, 172°, etc.
3.) Reflex angles: These are angles greater than 180° but less than 360°. Examples are 185°, 197°, 202°, 274°, 318°, 321°, etc.
4.) Complementary angles: are angles formed when two angles add up to 90°. For examples:
41° + 49° = 90°.
41° and 49° are complements to each other.
63° + 27° = 90°
63° and 27° are complements to each other.
5.) Supplementary angles: are angles formed when two angles add up to 180°. For example:
94° + 86° = 180°; Angle 94° is supplement to 86°.
123° + 57° = 180°.
123° and 57° are supplements to each other.
Exercises
Use a protractor to draw the following angles:
1.) 48°
2.) 125°
3.) 169°
4.) What is the complentary angle of 39°?
5.) The supplementary angle of 62° is ______________