Surface Areas and Volumes of Spheres GEOMETRY LESSON 10-7 10. 20 cm2 11. 154 in.2 12. ft3; 524 ft3 13. 288 cm3; 905 cm3 14. in.3; 1767 in.3 15. cm3; 2145 cm3 16. 2304 yd3; 7238 yd3 17. 98.784 m3; 310 m3 18. 451 in.2 19. 1006 m2 20. 130 cm2 21. S.A. ≈ 108 cm2; V ≈ 108 cm3 1. 900 m2 2. 400 in.2 3. 1024 mm2 4. 40,000 yd2 5. 4624 mm2 6. 576 cm2 7. in.2 8. 62 cm2 9. 232 in.2 Pages 560-564 Exercises 121 16 500 3 1125 2 2048 10-7

Surface Areas and Volumes of Spheres GEOMETRY LESSON 10-7 25. Answers may vary. sample: (5, 0, 0), (0, 5, 0), (0, 0, 5), (–5, 0, 0), (0, –5, 0), (0, 0, –5) 26. A: on; B: inside; C: outside 27. 1.7 lb 28. 8 in. sphere; the volume of the three spheres is 13.5 and of the large sphere is 85 . 29. m3 30. 36 in.3 31. ft3 32. mm3 33. yd3 34. 288 cm3 35. m3 36. mi3 37. a. 457 in.3 22. a. a sphere of radius 4 b. units3 c. 64 units2 23. Yes; the volume of the frozen yogurt is cm3, and the volume of the cone is 64 cm3. 24. a. 3 in. b. 102.9 in.3 256 3 1 4 9 2 500 125 6 343 1125 10-7

Surface Areas and Volumes of Spheres GEOMETRY LESSON 10-7 44. a. 6 3 in.; 3 3 in. b. 371.7 in.3 45. r ≈ 7.1 cm, h ≈ 14.1 cm 46. r ≈ 8.2 cm, h ≈ 11.4 cm 47. 707 cm2 48. a. Cube; 39. (continued) height 4 in. 40. 22 cm2; cm3 41. 26 cm2; cm3 42. 22 cm2; cm3 43. Answers may vary. Sample: You could lift the small ball because it weighs about 75 lb. The big ball would be much harder to lift since it weighs about 253 lb. 37. (continued) b. 228 in.3 c. 11 in. 38. a. about 8.9 in.2 b. The answer is less than the actual surface area since the dimples on the golf ball add to the surface area. 39. Answers may vary. Sample: sphere radius 3 in.; cylinder radius 3 in., 2 3 46 62 14 10-7

Surface Areas and Volumes of Spheres GEOMETRY LESSON 10-7 53. H 54. D 55. H 56. C 57. I 58. C 59. [2] a. S.A = 4 r2 36 = 4 r2 9 = r2 r = 3 ft 4 3 48. a. (continued) Explanations may vary. Sample: If s3 = r3, then s = r. So 6s2 = 6 r 2 ≈ 15.6r2 > 4 r2. b. Answers may vary. Sample: Spheres are difficult to stack. 49. 3 m 50. 15 m 51. 2 : 3 52. B 10-7

Surface Areas and Volumes of Spheres GEOMETRY LESSON 10-7 4 3 64. 109, 109, 71, 71 65. 10.5 cm 66. 27 cm 67. 67.5 cm2 59. [2] (continued) b. V = r3 V = 33 V = 36 ft3 [1] one computation error 60. 16 m3 61. 19 in.3 62. 19,396 mm3 63. 35, 55 10-7