Geometry: An Interactive Journey to Mastery

Solutions

8. D௘ͽ $PRXQWRIR[\JHQQHHGHGGHSHQGVRQYROXPH$PRXQWRIR[\JHQDEVRUEHGGHSHQGVRQVXUIDFHDUHD
   E௘ͽ k = 5, so SA k^2 = 100 cm^2 and V = 2k^3 = 250 cm^3.
   F௘ͽ 7KHUDWLRSAV is 2 2 for the small worm and^100250  for the big worm. This is much worse for the
   big worm.
   G௘ͽ 7KHUDWLRSAV ZRXOGEHFRQVLGHUDEO\ZRUVHIRUDIRRWZRUP8QOLNHO\WRVXUYLYH


9. D௘ͽ k^3  SRXQGV
   E௘ͽ Âk = 12 inches.
   F௘ͽ AAklittle |S©¹ ̈ ̧§· 21 2 0.786 in , and^222 big| 0.786 113.097 in.
   G௘ͽ Little||2 .07u^20086 127 lbs/in.^2
   Big||2 113.u 097 6112 lbs/ni^2.
   H௘ͽ 0RVWOLNHO\QRW


10. D௘ͽ k 1001 , so weight = 120k^3 = 0.00012 pounds, and SA = 10k^2 = 0.001 ft^2.
    E௘ͽ 9ROXPHRIZDWHU î IW^3. This weighs 0.7 pounds, which is 120 0.7  of her weight.
    F௘ͽ 9ROXPHRIZDWHU î IW0.00007^3. This weighs 0.00007 pounds, which is
    0.00012| of her body weight. She would not be able to move.
    Lesson 25


11. Probability 12.


12. D௘ͽ .
    E௘ͽ 113.