Page 233 - Maths Skills - 7

Answers 231

3. (i) – 56 (ii) – 40 4. (i) 20 (ii) 17 5. – 17545 6. 36323 7. y = – 11 8. x = 4
6
13 –34
9. b = 5 10. 3
Assessment Time
A. 1. (i) 2. (i) 3. (ii) 4. (i) B. 1. constant 2. trinomial 3. constant term 4. 8
5. – 8b C. 1. F 2. F 3. T 4. F 5. T D. 1. 6x + 14x – 17
2
2. 4x – 21x + 32 E. 1. (c) 2. (a) 3. (a) F. 1. ` (20 + 10)n 2. ` 534 3. 2
2
HOTS

y 20
1. 5w + 3x − 2. 3. –9x + 21y + 5z + 2 4. x – 12 = 2(x – 17)
2z 7
Chapter - 8: Perimeter and Area

Boot-up
A. 1. (ii) 2. (iv) 3. (ii) 4. (i) B. 1. Area 2. Perimeter 3. area 4. no. of sides
C. 1. F 2. T 3. T 4. F

Exercise - 8.1
1. (i) 100 cm (ii) 250 cm (iii) 60 cm (iv) 95 cm 2. (i) 44 cm (ii) 132 m (iii) 198 m (iv) 66 cm
3. 12 cm 4. 1800 m, ` 3600 5. 14 cm 6. 2200 m 7. 35 cm, 8.75 cm
8. (i) 22 cm (ii) 44 cm (iii) 0.88 m (iv) 39.16 m 9. 14 m 10. length = 600 m; breadth = 300 m
Exercise - 8.2
1. (i) 38.44 cm (ii) 23.04 cm (iii) 42.25 m 2 2. (i) 22.5 cm (ii) 44.1 dm 2 (iii) 36.8 m 2
2
2
2
3. 8 cm, 64 cm 4. 60 m 5. ` 504 6. 1250 tiles 7. Diagonal = 10 2 cm or 14.14 cm 8. 1.346 m 9. 5 m
2
10. 50 cm 2 11. ` 1800
Exercise - 8.3
2
1. (i) 1091.5 m (ii) 208.5 m 2 2. 306.25 m 3. 424 m ; ` 20808 4. ` 2310 5. ` 2640
2
2
6. Single shaded = 650 m ; Double shaded = 50 m 2 7. (i) 556 m (ii) 93 m 2
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2
Exercise - 8.4
1. 48 cm 2. 9 cm 3. Height = 6 cm, Base = 18 cm 4. Base = 14 m, Altitude = 28 m 5. 21 cm
2
6. ` 12150 7. 24 cm 8. 9.6 cm 9. (i) 90 cm (ii) 220 cm (iii) 75 m (iv) 750 cm 10. 384 cm 2
2
2
2
11. 6 cm 10 cm 12. 45 cm, 27 cm; 432 cm 2
Exercise - 8.5
2
2
2
1. (i) 120 m (ii) 75 m (iii) 108 m (iv) 62.5 m 2 2. 5 39 cm or 31.23 cm 2 3. 10 cm, 15.93 cm
2
4. 120 cm 5. 60 cm 6. 100 m 7. 8 units 8. 10 3 cm 9. 8 units 10. Height = 50 m; Base = 200 m
2
2
11. ` 12500 12. (i) 16 3 cm (ii) 36 3 cm (iii) 26.01 3 cm 2
2
2
Exercise - 8.6
1. 75.46 cm 2. ` 2625 3. 2464 cm 4. 49 m 5. 46.585 cm 6. 4400 m 7. 13 cm 8. 28 m
2
2
2
2
9. 168 cm 10. ` 10560 11. 98 cm 2 12. 23.852 cm 2
2
Assessment Time
A. 1. (iv) 2. (iii) 3. (iii) 4. (i) 5. (iii) 6. (ii) 7. (ii) 8. (ii)
B. 1. Base × Altitude 2. 3 × side 3. circumference 4. area 5. 100 ares, 10,000 m 2
6. 2 (length + breadth) 7. 4 × side C. 1. T 2. T 3. T 4. F 5. T
6. T 7. T 8. F 9. F 10. T D. 1. ` 20,475 2. 300 cm 3. ` 7500
E. 1. (d) 2. (a) 3. (a) F. 1. ` 2310 2. ` 2640 3. (i) 75 cm 2 (ii) ` 146.25
4. 365.75 m , ` 5220 5. 96 cm 6. 40 cm 7. 16 cm
2
2
2
G. 1. 44 sq meters 2. ` 46,20,000 3. 5 × 3 or 3 × 5