急! F5 Trigonometry 11q4

皆是用了正弦定理和餘弦定理

14.
(a)
1^2=4^2+3.2^2-2(4)(3.2)(cosDBC)

DBC=9.6201

(b)
4^2=1^2+3.2^2-2(1)(3.2)(cosBDC)

BDC=138.0518

BDA=180-BDC=41.9482

BAC=180-70+9.6201-41.9482=77.6719

(c)
AB/sin41.9482=3.2/sin(BAC)

AB=2.1896(m)



15.
AB/sin(180-32)=7/sin(180-32)= 2/sin(BAP)

BAP=8.7083

DAP=180-90-8.708=81.2916

DX/sin(DAX)=DX/sin(81.2916)=3/sin90

DX=2.9654(m)


7/sin90=C'C/sin(BAP)

C'C=1.0898

C'C+DX=CY=4.0253(m)

圖:
http://blog.yimg.com/3/TMAhyXR7s59ewiOunE_dQQkZpl769MhyMUsABD_K6JDXaMNLPHt52w--/55/l/lOuaO6_rqZ_FWaDCwzycUg.jpg