AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

SCERT AP 7th Class Maths Solutions Pdf Chapter 12 Symmetry InText Questions and Answers.

AP State Syllabus 7th Class Maths Solutions 12th Lesson Symmetry InText Questions

[Page No. 99]

Look at the following picture and speak about what you have noticed regarding symmetry in the picture.
AP AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 17th Class Maths Solutions 12 Symmetry InText Questions 1
Question 1.
What do you observe in this picture?
Ducks have symmetry.
Wall paintings have symmetry.
Butterfly has symmetry.
Clock tower and gaint wheels have symmetry.

Question 2.
Can you name the different shapes in picture?
Answer:
Hexagon, Circle, Rectangle, etc.

Question 3.
Which figures are looking attractive and beautiful? Why?
Answer:
Flooring, Gate arch and wall painting are beautiful as they have lines of symmetry.

AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

Question 4.
Which figures are in symmetry?
Answer:
Ducks, wall paintings, gaint wheel and the clock tower have symmetry.

Question 5.
Can you draw line(s) of symmetry for them?
Answer:
Yes.

[Page No. 100]

Look at the following figures. If we fold them exactly to their equal halves, one half of each figure exactly coincides with other half.
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 2
Question 1.
What do we call such figures?
Answer:
Symmetric figures or shapes.

Question 2.
What do we call the line along which we fold the figures so that, one half coincides with the other?
Answer:
Line of symmetry.

Let’s Explore [Page No.102]

Question 1.
Find relation between the number of sides of regular polygon and its lines of symmetry.
Answer:
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 3
From the above table, we conclude that the number of sides of a regular polygon is equal to its number of lines of symmetry.

AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

Question 2.
How many lines of symmetry can be drawn to a circle?
Answer:
Number of lines of symmetry can be drawn to a circle are infinite.

Let’s Think [Page No. 103]

Question 1.
Draw any three shapes basing on below sentences :
(i) no line of symmetry
Answer:
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 4

(ii) one line of symmetry
Answer:
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 5

(iii) two lines of symmetry
Answer:
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 6

(iv) three lines of symmetry
Answer:
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 7

Check Your Progress [Page No. 105]

Find whether the following letters of the English alphabet have rotational symmetry or not. If yes, find the point of rotational symmetry (approximately), and also order of rotational symmetry.
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 8
Answer:
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 9

Check Your Progress [Page No. 107]

Look at the following pictures and write their angle of symmetry and order of symmetry.
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 10
Answer:
(i) Spinner: Angle of symmetry = 120°
Order of symmetry = 3

(ii) Gaint wheel : Angle of symmetry = 60°
Order of symmetry = 6

AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

[Page No. 108]

Tesselations: The majority of the objects what we use in daily life have atleast one type of symmetry. Most of the machine made products are symmetric.

Observe these patterns :
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 11
(i) Where do you see these?
Answer:
We see these patterns in floor designs and fabric painting etc.

(ii) How these patterns are formed? Are they symmetric as whole?
Does the basic figure which is used to form the tessellations symmetric?
Answer:
You can observe that only some patterns have symmetry as a whole as in fig(i) and (ii), through the basic figures/unit figures are symmetric. Observe the fig(iii). You may notice that the two shapes can observe as ‘Basic or unit figures’ which is square or hexagon used to draw tessellation.

Usually, these patterns are formed by arranging congruent figures side by side in all the directions to spread upon an area without any overlaps or gaps. This is called tessellation. This enhances the beauty of the diagrams.

Let’s Explore [Page No. 109]

Fill the following with different colours to get beautiful tessellation patterns.
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 12
Answer:
Not needed.
Student should colour it on his own.

Let’s Explore [Page No. 109]

Construct a square having side 3cm. Draw all possible lines of symmetry. (Steps of construction is not necessary)
Answer:
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 13

  1. Let ▢ABCD be the square with side 3 cm.
  2. AC, BD, LM and PQ are lines of symmetry.

Examples:

Question 1.
If an equilateral triangle ABC is rotated through 360° about the point of rotation ‘P’ (i.e., point of intersection of angle bisectors), it attains the original form three times upon rotation through 120°, 240° and 360° as shown below.
Answer:
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 14
Clearly, the above figure possesses a rotational symmetry of order 3.

AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

Question 2.
While rotating the following figure through 360° about the point ‘O’ (mid-point of BC), it attains the original form twice (upon rotation through 180° and 360°) as shown below.
Answer:
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 15
Clearly, the above given figure possesses a rotational symmetiy of order 2.

Question 3.
Check whether the letter ‘S’ has point symmetry.
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 16
Answer:
Yes, it has a point symmetry.
Because, in the given figure, we have
i) Every part of the letter has a matching part are at the same distance from the central point.
ii) The part of the alphabet and its matching part are in the opposite direction.

[Page No- 111]

The image of an object as seen in a mirror is known as mirror image./In mirror image of an object, right side of the object appears at left side and vice versa. There are some objects whose mirror images are identical to the objects. For example, 11 capital English alphabets whose mirror images remain unchanged. They are A, H, I, M, O, T, U, V, W, X and Y.

Mirror Images of English Alphabets and some numbers :
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 17

Practice Questions [Page No. 112]

Choose the correct mirror image of the given words.

Question 1.
LATERAL
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 18
Answer:
(b)

Question 2.
QUANTITATIVE
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 19
Answer:
(d)

Question 3.
JUDGEMENT
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 20
Answer:
(c)

AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

Question 4.
EMANATE
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 21
Answer:
(b)

Question 5.
KALINGA261B
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 22
Answer:
(d)

Question 6.
COLONIAL
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 23
Answer:
(d)

Question 7.
BR4AQ16HI
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 24
Answer:
(a)

Question 8.
R4E3N2U
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 25
Answer:
(c)

Question 9.
DL3N469F
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 26
Answer:
(b)

Question 40.
MIRROR
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 27
Answer:
(d)

Water images [Page No. 112]

The reflection of an object as seen in water is known , as water image. The upper part of the object seen downward and vice-versa. There a re some objects whose water images are identical to the objects. For example, 9 cap ital English alphabets given below, whose water images remain unchanged. They ar e B, C, D, E, H, I, K, O and X.
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 28

AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

Practice Questions [Page No. 113]

Choose the correct water image of the given words.

Question 1.
KICK
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 29
Answer:
(d)

Question 2.
UPKAR
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 30
Answer:
(a)

Question 3.
KID
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 31
Answer:
(b)

Question 4.
SUBHAM
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 32
Answer:
(c)

Question 5.
CHIDE
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 33
Answer:
(d)

Question 6.
HIKE
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 34
Answer:
(a)

Question 7.
COT5E
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 35
Answer:
(a)

AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

Question 8.
ab45CD67
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 36
Answer:
(b)

Question 9.
abc
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 37
Answer:
(a)

Question 10.
01234
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 38
Answer:
(a)

Mirror image of the clock [Page No. 114]

1. A clock is a device provided with three hands an hour hand, minute hand and second hand.
Hours hand also known as short hand and minutes hand is also known as long hand.
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 39

2. The face of the clock is divided into 12 equal divisions.
The angular space between any two consecutive divisions has further divided into five more divisions.
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 40
Let us observe the following images of a clocks and their mirror images :
Case I: To find the time in the mirror image subtract the actual time from 11 hours 60 minutes.
AP Board 7th Class Maths Solutions 12 Symmetry InText Questions 41
Example 1:
If actual time in clock is 9 hours 30 minutes then, what is’the time shown in mirror?
Answer:
11 hrs 60 min – 09 hrs 30 min – 2 hrs 30 min

AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

Example 2 :
If actual time in clock is 7 hours, then what is the time shown in mirror?
Answer:
11 hrs 60 min – 07 hrs 00 min = 4 hrs 60 min = 5 hrs (1 hour — 60 minutes)

Case II : If the time in clock is between 12 hrs and 01 hr then to find the time in the mirror image subtract the actual time from 23 hr 60 min.
Example :
If actual time in clock is 12 hours T5 minutes, then what is the time shown in mirror?
Answer:
23 hrs 60 min — 12 hrs 15 min =11 hrs 45 min

Practice Questions [Page No. 114]

Choose the correct mirror image of the given words.

Question 1.
If actual time in dock is 06 hours 10 minutes, then what is the time shown in mirror?
(a) 3 hr:s 50 min
(b) 4 hrs 50 min
(c) 5 hrs 50 min
(d) 6 hrs 50 min
Answer:
(c) 5 hrs 50 min

Question 2.
If actual time in clock is 03 hours 54 minutes, then what is the time shown in mirror?
(a) 8 hrs 06 min
(b) 9 hrs 06 min
(c) 8 hrs 54 min
(d) 9 hrs 54 min
Answer:
(a) 8 hrs 06 min

Question 3.
If actual time in clock is 08 hours 26 minutes, then what is the time shown in mirror?
(a) 6 hrs 34 min
(b) 3 hrs 34 min
(c) 1 hr 34 min
(d) 3 hrs 36 min
Answer:
(b) 3 hrs 34 min

AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

Question 4.
If actual! time in clock is 4 hours, then what is the time shown in mirror?
(a) 7 hrs
(b) 7 hrs 30 min
(c) 8 hrs
(d) 8 hrs 30 min
Answer:
(c) 8 hrs

Question 5.
If actual time in dock is 10’o clock, then what is the time shown in mirror?
(a) 2 hrs
(b) 3 hrs
(c) 4 hrs
(d) 5 hrs
Answer:
(a) 2 hrs

Question 6.
If the time shown in mirror is 10 hours 05 minutes, then what is the actual time in clock?
(a) 1 hrs 55 min
(b) 1 hrs 35 min
(c) 1 hrs 25 min
(d) 12 hrs 15 min
Answer:
(a) 1 hrs 55 min

Question 7.
If the time shown in mirror is 02 hours 47 minutes, then what is the actual time on the clock?
(a) 6 hrs 13 min
(b) 7 hrs 13 min
(c) 8 hrs 13 min
(d) 9 hrs 13 min
Answer:
(d) 9 hrs 13 min

Question 8.
If actual time in clock is 11 hours 45 minutes, then what is the time shown in the mirror?
(a) 1 hrs 15 min
(b) 3 hrs 15 min
(c) 6 hrs 15 min
(d) 12 hrs 15 min
Answer:
(d) 12 hrs 15 min

Question 9.
If actual time in clock is 12 hours 45 minutes, then what is the time shown in the mirror?
(a) 9 hrs 15 min
(b) 10 hrs 15 min
(c) 11 hrs 15 min
(d) 12 hrs 15 min
Answer:
(c) 11 hrs 15 min

AP Board 7th Class Maths Solutions Chapter 12 Symmetry InText Questions

Question 10.
If actual time in clock is 12 hours 12 minutes, then what is the time shown in mirror?
(a) 11 hrs 42 min
(b) 11 hrs 48 min
(c) 10 hrs 48 min
(d) 12 hrs 42 min
Answer:
(b) 11 hrs 48 min