1.AB之垂直距离为何?$ l0 `5 c" Q+ ~) t
b. 19.6506 $ u6 Z8 o; _5 P' T2.∠ABC之角度为何?# V, e+ @' m% L: B0 G0 @0 u
a. 51.589° b. 51.895° c. 51.985°' d( O. p$ c5 }+ V) h7 p. w4 f) L
3. 红色剖面线区之面积为何? ( Z) Z0 j3 |, L# }) E c. 108.98153 k- @3 [' x4 S" y( Q7 R
4. 绿色剖面线区之周长为何? * I, g# y. x& M3 y% `: t Y$ F9 S! c b. 100.8473