【进阶级练习题68】# g X" G1 ~* r
" O4 J) i! ^& y3 n* W+ ]" c. M
求:5 n! ]0 q8 J* u0 _! z" p
1. ∠a 之角度值为何?2 v$ j- x' i0 P% Y! h2 z
a. 57.296° b. 57.692° c. 57.926°0 \8 _ L% z( M: U. G! Z7 k* E J: f
2. 剖面线区域之面积为何? ( c* @( G! o0 K8 U4 K3 W! W, U- Y4 s6 V a. 1562.5000 b. 1562.5010 c. 1562.5100 4 b) ^$ k" b L) V& N3. 剖面线区域型心之y座标为何? 6 N9 r* m: F( B9 ]+ x7 S4 M, a& } a. 60.7227 b. 60.7272 c. 60.7722