Page 314 - ICSE Math 7

7. B(5, –4); C(–5, –4) 8. Q(3, 2); R(3, – 2) Y
9. (a) order 2 (b) order 2 4
(c) No rotational symmetry (Reflection in 3
(d) order 4 (e) order 4 (f) Order 2 (g) order 3 y-axis) 2 P
(h) No rotational symmetry X' P" 1 X
(b) O
Mental Maths –4 –3 –2 –1 –1 1 2 3 4
P'
1. (a) (iv) (b) (ii) (c) (iii) (d) (iv) (e) (iii) –2 (Reflection in
(f) (iv) (g) (ii) –3 x-axis)
2. (a) True (b) False (c) True (d) False (e) True –4
3. (a) anticlockwise (b) translation (c) 8 (d) 1 (e) 120° Y'
5. 3 6. (a) 2 (b) 3 (c) 2 (d) 6
4. (a) (b) 7. (a) 4; 90° (b) 4; 90° (c) 6; 60° (d) 1; 360°
8. (i) Both (a) and (b) (ii) only (a) (iii) only (a)
9. Toy B (symmetrical) is good for the market.

(c) (d) Think Smart
1. 90°, 135°, 180°, 225°, 270°, 315°, 360°.
2. (a) 90° (b) 180° (c) 90° (d) 270°
Practice Time
Chapter 19
1. (a) (b) Exercise 19.1
1. (a) white board marker, a pencil cell
(b) a funnel, an icecream cone
(c) a chalk box, a rubix cube
(c) (d)
(d) a marble, a soccer ball
2. (a) (v) (b) (i) (c) (ii) (d) (iv) (e) (iii)
3. Faces (F) 6 6 7
2. (a) (b) (c)
Edges (E) 12 9 15

Vertices (V) 8 5 10
Y
4 F + V – E 2 2 2
A' 3 A
2 Exercise 19.2
1 1. (d) and (e) 2. (a) and (d)
3. X' B' O B X 3. (a) (iii); (b) (v); (c) (iv); (d) (ii); (e) (i)
–5 –4 –3 –2 –1 1 2 3 4 5
–1
–2 1 1
–3 4. (a) 2 3 5 4 (b) 3 2 4 5
–4 6 6
Y'
Y
4 1 4
B' 3 (Reflection in (c) 2 6
A"
A 2 y-axis) 3 5
1
4. (a) X' O X
–4 –3 –2 –1 1 2 3 4
–1 5.
A' –2
(Reflection in –3
x-axis)
–4 (Note: Answers may vary)
Y' 6. (b) and (c)

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