【进阶级练习题90】 8 g# w' ]' p) K! p& p. d9 [. Q& o% ^) r& u
求: " ^% U% {: H% A6 k0 k1 C' R1. a 之长度为何?4 R p$ ~; L; u" O' b q
a. 76.7064 b. 76.7406 c. 76.7604 $ ]9 v z6 d0 [7 W$ V1 [2. b 弧之长度为何?! S1 l; B }6 ?1 T B8 d9 r: ~
a. 68.5273 b. 68.5372 c. 68.5723- G5 J% u, N/ m
3. 剖面线区域之面积为何?/ I' ?! {# Z% h" Y
a. 443.5255 b. 443.5525 c. 443.5552