【基础级练习题63】 - D( I4 M, ?5 ~% N2 `
! |$ ~' W9 D: d0 _, I6 j求: ! u1 g+ w; j- M
1. A弧之弧长为何?
7 i, @7 w+ P7 w- ~; p1 U$ S- u (A) 39.2699 (B) 39.2969 (C) 39.2996
# ]3 N6 v9 V- |' M" P; c' e6 e0 a2. B弧之弧长为何?
8 X& b& Q( n$ h (A) 78.5398 (B) 78.5893 (C) 78.5938
( V3 W! I- q2 n7 [+ d" J3. C弧之弧长为何?
8 D% F( L# n+ S' a (A) 41.0359 (B) 41.0593 (C) 41.0935 ! c$ e: p6 l9 a. V
4. 剖面线区域之面积为何?
$ ~5 W" f" x0 T# i1 J (A) 2862.6778 (B) 2862.6787 (C) 2862.6877 4 E3 }6 E0 _2 `: T
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【基础级练习题63】标准答案:
8 M7 ]1 H/ v. i" ]0 |" h1. A弧之弧长 = 39.2699,就是(A) . |2 `+ O+ ^2 r/ g2 X/ t1 C
2. B弧之弧长 = 78.5398,就是(A) ' W/ C8 t2 a( U
3. C弧之弧长 = 41.0593,就是(B) # g. `* u5 |/ f$ v! F
4. 剖面线区域之面积 = 2862.6877,就是(C) : l, q# o, E! k' {
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【基础级练习题63】解题思路:
Z: t8 m( @1 S- d$ {$ }6 b本题的关键点,是利用各圆心画与圆相切的圆,有相交相切圆,由包含相切圆。还有就
+ J9 j3 ^5 H& M7 ]! @是圆弧的偏移,虽比较简单,但还是很值得一练。/ `: g; L. x# `8 M2 z7 {! x2 t7 Y
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