练习题90答案:( R$ z% O+ j# [! ~' F; b
1. a 之长度为何?5 D! Q' H; l8 K
c. 76.7604 ( A$ m- I1 T. F) x- F2. b 弧之长度为何? . Z% E: O- G2 y( F5 Z4 {- ~ c. 68.5723& C" m# d0 B* H% C
3. 剖面线区域之面积为何? 1 Z y. _& a! B0 ?4 T a. 443.5255
1. a 之长度为何? c. 76.7604% q5 d8 o) s E) s* a
2. b 弧之长度为何? c. 68.5723 ) \6 v6 w3 `0 ]* f' ?7 V+ [3. 剖面线区域之面积为何? a. 443.5255 ) m% S$ z" d; w/ w: F: t ' l1 I& Z9 s1 u+ L! K