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2. Shapes and Angles
Rohini and Mohini are twin sisters. They love doing the same things. One day when they were making shapes with matchsticks, Shaila gave them a challenge.
Rohini made this shape.
Mohini  Is it a closed shape or an open shape?
Rohini  It is a closed shape.
Mohini  How many sides are there?
Rohini  It has 6 sides.
Mohini made this.
Now you give the answers.
Is it a closed shape??
Does it have 6 sides?
But it is not the same as the one made by Rohini. So Mohini tried again.
This is what she made.
Is it a closed shape with 6 sides?
Is it the same as the one made by Rohini?
Is there some way to say in what way these shapes are different?
 Mohini tried again but got different shapes. Guess and make two more shapes Mohini could have made.
Mohini is now tired of trying and asks Shaila what to do.

Look at the angles marked in these shapes. Can you see the difference?
 Look at the shape and answer.
 Answer these.
 Are the angles marked with yellow equal? ?
 Are the angles marked with green equal??
 Are the angles marked with blue equal? ?
 Are the angles marked with yellow equal? ?

Four different angles are marked in four colours. Can you find other angles which are the same as the one marked in red? Mark them in red. Do this for the other colours.

How many different shapes can you make by changing the angle between the matchsticks in each of these? Try.
Rohini and Mohini went all around with the angle tester to look for different angles in their class.
Rohini tested the angle of the Maths book and the pencil box.
 Go around with your tester and draw here those things in which the tester opens like the letter L. Are you sure they are all right angles? ,

Look at the angles in the pictures and fill the table.

Sukhman made this picture with so many angles.
 right angles with black colour.
 angles which are more than a right angle with green.
 angles which are less than a right angle with blue.

Draw anything of your choice around the angle shown. Also write what kind of angle it is. The first one is done.
In my name there are 11 right angles. There are also 10 angles less than a right angle.
 Write 3 names using straight lines and count the angles.
Changing Shapes
Things you need  used (or new) matchsticks. Piece of rubber tube used in cycle valves.
 Clean the black end of the matchsticks.
 Cut small pieces of the tube (about 1 cm long).
 Push two matchsticks into each end of a tube piece.
 Add more matchsticks to form a triangle.
Now make these 4, 5, 6 sided shapes by using tube pieces and matchsticks.
 Find out how many angles are there in each of these shapes. Mark them.
 Find out and write your results in the table given.
Now push each shape downwards with the tip of your finger.
Does the angle change when pushed down by the finger?
Shapes and Towers
Look for triangles in the pictures below.
 From the activity 'Changing Shapes' can you guess why triangles are used in these towers, bridges etc?
 Look around and find out more places where triangles are used.
Angle and Time

There are many times in a day when the hands of a clock make a right angle. Now you draw some more.

Write what kind of angle is made by the hands at these times. Also write the time.

Draw the hands of the clock when they make an angle which is less than a right angle. Also write the time.
Degree Clock
Appu and Kittu are playing carromboard. Appu hit the striker.
 In the picture three points A, B and C are shown. Draw a line to show from which point Kittu should hit to get the queen.
Angles with Yoga
Rahmat is doing Yoga. These are the pictures of different ‘Asanas’ he does everyday.
The D Game
You can play the 'D' game with your friends. You draw an angle. Your friend will guess the measure of that angle. Then you use your 'D' to measure it. The difference between the measured angle and the guess will be your friend’s score. The one with the lowest score will be the winner.