【进阶级练习题90】 : _+ n% v6 W. M1 \ * I( Y! W5 d" W/ W求: $ B s7 m, T8 s4 _, |: v1. a 之长度为何?* D7 q; |7 S( {5 d7 ^2 r7 t
a. 76.7064 b. 76.7406 c. 76.76048 ]+ S# o* c7 U5 Y
2. b 弧之长度为何?; F3 X+ C) @2 ]* ^3 c3 ^5 e2 T; ^
a. 68.5273 b. 68.5372 c. 68.57237 ]- H! }) b& [2 W& o
3. 剖面线区域之面积为何?+ V* N$ ~2 `( y4 b
a. 443.5255 b. 443.5525 c. 443.5552