A student used a protractor to measure the angles as shown below. (Page 44)

A student used a protractor to measure the angles as shown below. Class 6

Question 1.

A student used a protractor to measure the angles as shown below. Class 6

In each figure, identify the incorrect usage(s) of the protractor and discuss how the reading could have been made, and think about how it can be corrected.

Solution:

In (i), the lower arm of angle U should coincide with the 0-0 line of the protractor.

Here, ∠U = 60°.

In (ii), the lower arm of angle V should coincide with the 0-0 line of the protractor.

Here, ∠V = 70°.

In (iii), vertex W of the angle must coincide with the centre of the protractor, and one of the arms should coincide with the 0-0 line of the protractor.

Here, ∠W = 75°.

In (iv), vertex X of the angle must coincide with the centre of the protractor.

Here, ∠X = 20°.

In (v), vertex Y of the angle must coincide with the centre of the protractor, and one of the arms must coincide with the 0-0 line of the protractor.

Here, ∠Y = 150°.

In (vi), angle Z should be measured using the outer scale of the protractor.

Here, ∠Z = 105°.