# Class 6 Maths Chapter 5 Exercise 5.2 Pdf Notes NCERT Solutions

Class 6 Maths Chapter 5 Understanding Elementary Shapes Exercise 5.2 pdf notes:-

**Exercise 5.2** Class 6 maths Chapter 5 Pdf Notes:-

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## Ncert Solution for Class 6 Maths Chapter 5 Understanding Elementary Shapes Exercise 5.2 Tips:-

**Introduction:-**

Angles – ‘Right’ and ‘Straight’

You have heard of directions in Geography. We know that China is to the

north of India, Sri Lanka is to the south. We also know that Sun rises in the

east and sets in the west. There are four main directions. They are North (N),

South (S), East (E) and West (W).

Do you know which direction is opposite to north?

Which direction is opposite to west?

Just recollect what you know already. We now use this knowledge to learn

a few properties about angles.

Stand facing north.

Turn clockwise to east.

We say, you have turned through a right angle.

Follow this by a ‘right-angle-turn’, clockwise.

You now face south.

If you turn by a right angle in the anti-clockwise

direction, which direction will you face? It is east

again! (Why?)

From facing north to facing south, you have turned by

two right angles. Is not this the same as a single turn by

two right angles?

The turn from north to east is by a right angle.

The turn from north to south is by two right angles; it

is called a straight angle. (NS is a straight line!)

Stand facing south.

Turn by a straight angle.

Which direction do you face now?

You face north!

To turn from north to south, you took a straight angle

turn, again to turn from south to north, you took another

straight angle turn in the same direction. Thus, turning by

two straight angles you reach your original position.

Think, discuss and write

By how many right angles should you turn in the same direction to reach your

original position?

Turning by two straight angles (or four right angles) in the same direction

makes a full turn. This one complete turn is called one revolution. The angle

for one revolution is a complete angle.

We can see such revolutions on clock-faces. When the

hand of a clock moves from one position to another, it turns

through an angle.

Suppose the hand of a clock starts at 12 and goes round

until it reaches at 12 again. Has it not made one revolution?

So, how many right angles has it moved? Consider these

examples :

From 12 to 6 From 6 to 9 From 1 to 10

1

2 of a revolution.

1

4 of a revolution

3

4 of a revolution

or 2 right angles. or 1 right angle. or 3 right angles.