Page 234 - Maths Skills - 7

232 Maths

HOTS
1. 1,044 tiles, ` 24,012 2. ` 1762.50
3. Shaded region in all cases = 182 cm , because in each case required area is area of rectangle minus circle.
2
Chapter - 9: Lines and Angles

Boot-up
A. 1. (iv) 2. (i) 3. (ii) 4. (iii) B. 1. angle 2. isosceles 3. hypotenuse 4. bisector
C. 1. T 2. T 3. F 4. F

Exercise - 9.1
1. (i) True (ii) False (iii) True (iv) False (v) False (vi) False (vii) True
2. (i) only two pairs of angles are supplementary (∠3, ∠4) and (∠4, ∠5) (ii) (∠3, ∠5)
(iii) (∠3, ∠4), (∠4, ∠5), (∠1, ∠2 , ∠3) and (∠1, ∠2 , ∠5) (iv) (∠1, ∠2), (∠2, ∠3), (∠3, ∠4), (∠4, ∠5) and (∠1, ∠5)
3. (i) Complementary (ii) Supplementary (iii) Supplementary (iv) Supplementary (v) Complementary
4. (i) 72° (ii) 102° (iii) 0° (iv) 45° (v) 35° (vi) 115°
5. (i) 55° (ii) 0° (iii) 45° (iv) 40° (v) 25° (vi) 22°
6. 30° 7. 90° 8. 80° 9. (i) x = 45° (ii) x = 65° (iii) x = 55° (iv) x = 100° (v) x = 97.5°
(vi) x = 80° 10. ∠2 = 105°, ∠3 = 75°, ∠4 = 105°

Exercise - 9.2
1. ∠2 =135°, ∠3 = 45°, ∠4 = 135°, ∠5 = 45°, ∠6 = 135°, ∠7 = 45°, ∠8 = 135° 2. x = 115° 3. x = 45°, y = 60°
4. (i) transversal (ii) same (iii) equal (iv) supplementary angles (v) adjacent (vi) (a) 180° (b) 135°
5. x = 17°, ∠1 = 56°, ∠2 = 124°, ∠3 = 124°, ∠4 = 56° 6. ∠1 = 112°, ∠2 = 105° 7. ∠DEF = 60° 8. x = 30°, y = 40°
9. x = 56°, y = 63° 10. (i) x = 55°, y = 125° (ii) x = 120°, y = 120°
Assessment Time

A. 1. (iii) 2. (i) 3. (ii) 4. (iii) 5. (iii) B. 1. parallel 2. 180°
3. the exterior angles 4. distance 5. equal C. 1. T 2. F 3. T 4. T
5. F D. 1. (iii) 2. (ii) 3. (ii) 4. (iii) 5. (ii) E. 1. (b) 2. (a)
3. (b) F. 1. Do it yourself 2. 36° G. (i) Road, 1, 2 (ii) Road, 3, 4, 5 (iii) Do yourself
(iv) Road – 3 (v) 12 (vi) Do yourself
HOTS

1. All pairs of alternate interior angles will also be equal. 2. (i) x = 255° (ii) y = 108°
3. (i) x = 80°, y = 140° (ii) x = 60°, y = 60° 4. (i) x = 54° (ii) x = 140°

Assessment - 3
1. (d) 2. (c) 3. (c) 4. (c) 5. (a) 6. 180° 7. 14
8. Sum of parallel side, distance between them 9. Polynomial 10. 3 11. (T) 12. (F) 13. (T)
14. (T) 15. (F) 16. 40 m, 80 m, 80 m, 17. 1440 m 18. ` 3650 19. (c) 20. (a)
2
2
2
2
2
21. 381 m 2 22. 2x – 9x – 3, –13 23. 33 cm 24. – a + 8b + 2ab + 4ab 25. 16.50 m 2 26. 462, 400 m 2
27. 125° 28. x = 135° y = 45° 29. ` 600 30. ` 12250
Chapter - 10: The Triangle and its Properties
Boot-up
A. 1. (iii) 2. (iv) 3. (iii) 4. (i) B. 1. 180° 2. obtuse angled triangle 3. scalene 4. 3, 3
C. 1. F 2. T 3. F 4. T

Exercise - 10.1
1. (i) six (ii) Three, three and three (iii) triangular (iv) two interior opposite angles (v) equal/60° (vi) 3,3
(vii) median 2. (i) Right angled triangle (ii) Obtuse angled triangle (iii) Acute angled triangle (iv) Acute angled triangle
3. (i) Isosceles (ii) Equilateral (iii) Scalene 4. (i) 58° (ii) 45° (iii) 30° (iv) 20°
5. (i) 20°, 60°, 100° (ii) 40°, 50°, 90° (iii) 36°, 72°, 72° (iv) 60°, 60°, 60°