Page 92 - Maths Skill - 6

90 Maths

Step 1: To measure ∠ABC, place the protractor in such a way that its centre lies on B C
and the arm BA coincides with the horizontal edge or base line of the protractor.
Step 2: Starting from 0° of the inner scale, move towards point C and note the mark on

the rim of the protractor where ray BC passes.
Step 3: Read the mark carefully taking care of smaller divisions also. B A
C

Thus, ∠ABC = 65°
B A

Exercise 6.2

1. Measure the angles given below using the Protractor and write down the measure.
(i) (ii) (iii) (iv)

2. Find the measure of the angle shown in each figure. (First estimate with your eyes and then find the actual
measure with a protractor).
(i) (ii) (iii) (iv)

3. Find the angle measure between the hands of the clock in each figure.
(i) (ii) (iii)

9:00 a.m. 1:00 p.m. 6:00 p.m.

TYPES OF ANGLES
We can classify the angles according to their degree measures. B
O A
Zero Angle Fig. (a)
An angle which measures 0° is called a zero angle.
Or
If the initial position and the final position of a ray coincide without making any revolution, then the angle formed
is called zero angle.

In Fig. (a), ∠AOB is a zero angle.