Page 348 - Start Up Mathematics_7

Exemplar Problems 4. (a) 1,820 m (b) 4,480 m 2 5. ` 5,100; ` 9,424
2
1. c 2. b 3. a 4. Isosceles 6. 3.375 m 7. (a) 520.6 m (b) 4,892 m 2
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5. False 6. False 8. 42 cm 9. 112 cm ; 60 cm 10. 79 cm 2
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7. Number of lines Order of rotational 11. Parallel Side 1 Parallel Side 2 Altitude Area
of symmetry symmetry (a) 14 m 20 m 8 m 136 m 2
(a) 0 2
(b) 6 mm 16 mm 14 mm 154 mm 2
(b) 1 1 (c) 60 cm 110 cm 1.4 m 1.19 m 2
(c) 0 3
(d) 1 1 12. (a) 40 (b) 5 (c) 32 13. 72 cm 2
14. Area (Fig. II) = 2 [area (Fig. I)]
8. No
 Fig. I is a trapezium
Chapter 14 5 11+
4
 ar (Fig. I) = ×= 32 cm 2
Exercise 14.1 2
1. (a) 40 cm, 96 cm (b) 70 m, 300 m Hence ar (Fig. II) = 64 cm 2
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2. (a) 64 cm (b) 13.52 cm 2 Perimeter (Fig. I) = 26 cm
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3. ` 36,000 4. 25 cm, 82 cm Perimeter (Fig. II) = 30 cm
15. 110 cm , 150 cm 2
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1
5. (a) 9 litre (b) ` 2,100
3 Review Exercises
6. (a) 62 cm, 122 cm (b) 60 cm, 72 cm Multiple Choice Questions
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7. (a) ` 94,710 (b) 10 rounds 1. a 2. d 3. b 4. c 5. c
8. Figure Length Breadth Area Perimeter 6. c 7. b 8. d 9. b
Square 13 cm 13 cm 169 cm 2 52 cm Solve Mentally
Rectangle 80 cm 3.2 m 2.56 m 2 8 m True or False
Square 1.21 m 1.21 m 1.46 m 2 4.84 m 1. True 2. True 3. True 4. False 5. False
9. 80 m 10. 64 poles 6. True 7. False 8. False 9. True 10. False
Exercise 14.2 Fill in the Blanks
1. (a) 15 cm 2 (b) 32 cm (c) 16 cm 1. 16 cm 2. 9 cm 3. square units, unit
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2
2
9 4. inscribed, less 5.  6. irrational
2. (a) 24 cm (b) 2 cm (c) 6 cm 3. 12 cm 7. 48 cm 8. height 9. 100
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2
2
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4. (a) 48 cm (b) 4 cm 5. 24 cm 10. 31 cm 2
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6. (a) 27 cm (b) 4.5 cm 7. 40 m 8. 36 m Answer in One Word or a Line
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9. 420 m 2
1. 54 cm 2. 64 m 3. 18 cm
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10. S. No. Figure Base Height Area 4. hectare; 1 hectare = 100 ares
1. Triangle 34 cm 18 cm 306 cm 2 22
2. Parallelogram 5.2 m 4.9 m 25.48 m 2 5.  ≠ , it is only an approximate value
3. Parallelogram 250 m 80 m 2 hectare 7
6. Both area and the perimeter of the circle is greater
Exercise 14.3
Let’s Evaluate
1. (a) 132 mm (b) 44 cm 2 2
1 1. 42 cm , 44 cm 2. 15.285 cm
2. (a) 1,257 cm (b) 1,386 cm 3. 6.3 cm 4. 4 : 5 3. ar (P) = 31.5 cm , ar (Q) = 35 cm , ar (R) = 76.5 cm 2
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2
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7
5. (a) 1,386 m (b) ` 2,640 6. 14 cm 4. 2.8 m
2
7. 300 revolutions 8. 1 : 9 9. 484 cm 2 Thinking Skills
10. 37.71 cm 11. 4 : 5 12. ` 18,240 1. 356 cm 2. 20 cm 3. 1,044 tiles; ` 24,012
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Exercise 14.4 4. Shaded region in all cases = 182 cm , because in each
case required area is area of rectangle minus circle.
1. 336 m 2. 200 m , 2,232 m 2 3. ` 2,46,50,000 5. 400 revolutions
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2
340