Do it yourself.
NCERT Textbook Page 99
Tangram
Look at the tangram set given at the end of your textbook. Cut out all the shapes. Name them.
(a) How are they same or different from each other?
(b) What do you notice about the angles of each of the shapes?
(c) What do you notice about the sides of each of the shapes?
Solution:
The given tangram consists of 7 pieces:
1. 2 large right triangles (the purple and the yellow)
2. 1 medium right triangle (orange)
3. 2 Small right triangles (the blue and the green)
4. 1 square (pink)
5. 1 parallelogram (the dark purple).
(a) They are same:
All the shapes are flat (2D).
All the shapes are polygons (made of straight lines).
Other than the parallelogram, all the shapes have at least one right angle (all the triangles are right triangles, and the square has four right angles).
They are different:
Number of sides and angles: The triangle have 3 sides and 3 angles.
The square and the parallelogram each have 4 sides and 4 angles.
Size: Tangram includes triangle of different sizes i.e., 2 large, 1 medium, 2 small.
(b) All the triangles: Each of the 5 triangles in the tangram set is a right-angled isosceles triangle.
The square: All four angles are right angles.
The parallelogram: It has two acute angles and two obtuse angles and opposite angles are equal.
(c) All the triangles: Since the triangle is an isosceles right angled triangle, so it has two equal sides and one longer side.
The square: All four sides are equal in length.
The parallelogram: It has two pairs of equal sides.
Opposite sides are equal in length i.e., the two longer sides are equal, and the two shorter sides are equal.
NCERT Textbook Page 100
Which Shape Am I?
Match the statements with appropriate shapes. Do some of them describe more than one shape?
Solution:
Kites
Make your own kite shape.
(a) Start with a square piece of paper.
(b) Take one corner of the paper and fold it towards the opposite corner, creating a sharp crease along the diagonal.
(c) Open and fold the corner A inwards, aligning the edge with the crease you just made.
(d) Repeat on the other side, folding the other corner B inwards to align with the crease at the centre.
You have a kite shape!
What shapes do you see in the kite?
Solution:
Three right-angled triangle in which two are of same size.
NCERT Textbook Page 101
Circle Designs
Can you think of a way to make a design exactly like the image given here? Try to make it.
Solution:
Do it yourself.
NCERT Textbook Page 102
Cube Connections