ݷʱ : 2024/12/25 14:27:55һ µȫĶ
AB=AG+GB12.5ף
𣺵ƸABĸ߶ԼΪ12.5ף 22⣺1BBEADڵE AB=40mA=30㣬
BE=AB=20mAE=
BADľΪ20m 2RtABEУ ߡA=30㣬 ABE=60㣬 ߡDBC=75㣬
=20m
EBD=180㩁60㩁75=45㣬 DE=EB=20m
AD=AE+EB=20+20=20+1m
RtADCУA=30㣬
DC==10+10m
CDΪ10+10m
23㡿ֱεӦéǸ⣻ֱεӦ鶽⣮
PPEOBڵEPFOCڵFPE=xAE=3xRtAEPиݹɶɵPE=
AE=3
CF=PF=mףOC=m+
סOA=m
3ףRtAOCУtan75=m̶ֵɵô𰸣
𡿽⣺PPEOBڵEPFOCڵF
i=13AP=10 PE=xAE=3x
RtAEPУx+3x=10
2
2
2
ãx=x=ᣩ
PE=AE=3
ߡCPF=PCF=45㣬 CF=PF
CF=PF=mףOC=m+ףOA=m3ף
RtAOCУtan75==m+=tan75?m3
ãm14.3
OC=14.3+17.5ף
ĸ߶ԼΪ17.5ף
24㡿ֱεӦã
1DDHABHDGCBABGƽıεжóDCBGΪƽıΣRtDGHУDH=DG?sin37DֱABľ룻
2ݣ1GHADAHijٸ··֮ΪAD+DGAGֵ㼴ɵó𰸣
𡿽⣺1ͼDDHABHDGCBABG DCAB
ıDCBGΪƽıΣ DC=GBGD=BC=11 RtDGHУ
DH=DG?sin37110.60=6.60 DֱABľ6.60km 2ݣ1ã
GH=DG?cos37110.808.80 RtADHУ
AD=DH1.416.609.31
AH=DH6.60
··֮ΪAD+DGAG
AD+DGAG=9.31+116.60+8.804.9km ڴAصBؿɱԭԼ4.9km
25㡿TBֱεӦé⣮
1⻭ͼΣٸƽߵʼֱεʽɣ 2ݼִӸۿAۿCõʱִͬBCõʱ䣬֪BCľ룬̶ִٶȣ 𡿽⣺1BDACڵDͼʾ
֪AB=301=30BAC=30㣬BCA=45㣬 RtABDУ
AB=30BAC=30㣬
BD=15AD=ABcos30=15
RtBCDУ
BD=15BCD=45㣬
CD=15BC=15
AC=AD+CD=15+15ACľΪ15+15
2AC=15+15
ִҴACʱΪ=+1