有幾條數學要大家幫忙計吓！麻煩大家！20點

1. 半球體總表面面積 = π r^2 + ½ (4 π r^2) 245π cm² = π r^2 + ½ (4 π r^2) 245π cm² = π r^2 + 2 π r^2 245 cm² = r^2 +2 r^2 3 r^2 = 245 cm² r = 9.037 cm半球體體積 = 1/2(4/3 π r^3) = 2/3 πr^3 = 2/3 π (9.037 cm)^3它的體積 = 1545.7 cm^3
2.球體表面面積= 4 π r^2球體體積 = 4/3 (π r^3)角錐體的體積 = (正方形底面積 x角錐體高度)/3 (a)半球體半徑 = r5^2 = r^2 + r^2 ( ~ 畢達哥拉斯定理)5^2 = r^2 + r^225 cm^2 = 2r^2r = 3.5355 cm AB = BC = CD = DA= s, ABCD 是正方形, 對角線AC和BD是半球體直徑AC^2 + AD^2 = BD^2s^2 +s^2 = (3.555 x 2)^22s^2 = 50s = 5 cm正方形ABCD底面積 = s^2 = 25 cm^2角錐體高度=半球體半徑 = 3.5355 cm角錐體的體積 = (正方形底面積 x角錐體高度)/3 = (25 cm^2 x 3.5355 cm)/3 – 29.4628 cm^3角錐體的體積 = 29.4628cm^3
(b) 球體積= 4/3 pi r^3 半球體體積 = ½ (4/3 π r^3) = 2/3(πr^3) = 2/3(3.1416 (3.5355)^3) cm ^3 半球體體積 = 2/3(3.1416 (44.1942)) cm ^3 半球體體積 = 92.56 cm ^3
© 餘下部分的體積 = 半球體體積 -角錐體的體積 餘下部分的體積 = 92.56 cm ^3 - 29.4628 cm^3 餘下部分的體積= 63.0973 cm^3