Page 185 - C:\Users\azizu\Documents\Flip PDF Professional\Matematics-Form-1-1\

From the results of Exploration Activity 2, it is found that
(i) the angle on a straight line is 180°. Thus, the sum of angles on a straight line is 180°.
(ii) a reflex angle is an angle with a size more than 180° and less than 360°.
(iii) the angle of one whole turn is 360°. Thus, the sum of angles at a point is 360°.

Self Practice 8.1c

1. For each of the following angles, state whether the angle is an angle on a straight
line, a reflex angle or an angle of one whole turn.
(a) (b) (c)

2. Copy each of the following diagrams. Identify and mark (i) the angle on a straight
line, (ii) the reflex angle and (iii) the angle of one whole turn. Explain how you
obtained your answers.
(a) 135° (b)
45° 78°
88° 72°
78°
30°

What are the properties of complementary LEARNING
STANDARDS
CHAPTER
8 angles, supplementary angles and conjugate Describe the properties
angles? of complementary angles,
supplementary angles
3 Classroom and conjugate angles.
Flip

Aim: To describe the properties of complementary angles, supplementary angles
and conjugate angles.
Instruction: • Explore by yourself before the lesson begins and discuss in groups
of four during the lesson.
• Open the folder downloaded from page vii.

1. Open the file Complementary angles.ggb using GeoGebra.

174
Chapter 8

08 TB Math F1.indd 174 11/10/16 12:17 PM