ѷDBCDB=CBջѷʤΤDB=4
äAD=2
ޤDP:BP=1:2
äBP=DB2/3
96ڡ 0:06:56 39749

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ġܣ£ġ᣶ꡢġᣲ
ȤϡģФȢã£Ф

£ãĤޤ֤Ȥͤơ㤤ޤ
ܿĻԡ 96ڡ 0:08:20 39750

ADαĹEȤ
Ѥ˴ؤPʿκѤꡢBDC=EDC=DCB
äơDB=DC
äơAD=2
ѷꡢBP=8/3
ϵ塡 96ڡ 0:09:42 39751
ͣ.ǥ
Ρ#39750ƱˡǤ
96ڡ 0:18:03 39752

5cm¸ߤ椹ޤ
ϳͤƱǡѤջѷˤʤ
ȤäƵޤ
裲롼ס 96ڡ 0:24:04 HomePage:39753

ɤִ֤
BC+AD+BD=10AC=5ܤABDEʿԻշȤʤE3:4:5ˤʤѥȤä12/5ʤƸääƤ

ʤˤäƤ
96ڡ 0:42:57 39754

BCʿԤʿԻշDBCEĤ롣
BDCCDE
ѤѤBDCBDBC4cmջѷǤ뤫顢
AD2cm
APD梤CPB1:2Ѥ
BP8/3
96ڡ 3:44:32 HomePage:39755

ۤƱǤAC=cmϣ碌ƤơȤ¡Ǥ礦
96ڡ 5:48:15 39756
abcba@baLLjugglermoka
BDCDC򼴤ޤ֤BιԤB'ȤСBDB'CʿԤˤʤȤޤǼĤɤ¤ꡢͳͤƱͤʲˡǤ͡
96ڡ 8:04:11 39757
AD164©
ADĹʿԻշޤʲͤȤäǤƹԤǤ
96ڡ 8:34:08 39758
Ȥ
ɸ֤ޤ

ADB=aȤȢBDC=(180-a)/2
ɸD(0,0),A(c,0),B(b,tan(a)*b),C(b-4,-(b-4)*tan((180-a)/2))Ȥ
tan((180-a)/2)=1/tan(a/2)ʤΤ
tan(2*a)=2*tan(a/2)/(1-tan(a/2)^2)Ȥä
B(b,2*tan(a/2)*b/(1-tan(a/2)^2)),C(b-4,(4-b)/tan(a/2))
tan(a/2)=aȤ
B(b,2*a*b/(1-a^2)),C(b-4,(4-b)/a)
AD//BCʤΤ 2*a*b/(1-a^2)=(4-b)/a ѷ
(4-b)*(1-a^2)=2*a^2*b(1)
AC=5
(b-4-c)^2+((4-b)/a)^2=25(2)
ޤAD=c,AD+BD=6BD=6-c(3)
b^2+(2*a*b/(1-a^2))^2=(6-c)^2
(1),(2)ϢΩȤmaximaDz򤯤
e1:(4-b)*(1-a^2)=2*a^2*b$
e2:(b-4-c)^2+((4-b)/a)^2=25$
e3:b^2+(2*a*b/(1-a^2))^2=(6-c)^2$
solve([e1,e2,e3],[a,b,c])$
part(%,9);[a=sqrt(7)/5,b=9/4,c=2]
ǢPBC梤PDA
c=AD=2(3)ȤBD=4 BC:AD=2:1=BP:PD ʤΤ
BP=4*2/3=8/3()
˭ԡ 96ڡ 11:52:36 MAIL:fttnm528@ybb.ne.jp 39759

Ĥ򱦤˱ĹƳ٤ξ狼ͤ
ѤˤDCB⢤ǡBD=BC2ջѷ
BD=4AD=2ưפˤ狼롣
ȤȤäƴλ

󡩣äƲ
96ڡ 12:08:26 39760
uchinyan
Ϥˤϡơϡ
ϴñǤʸ˥ҥܤʤΤǡǤʤȤ⤽񤷤ϤʤǤ礦
⤽äȻפޤʴǡ

BCD CD ˴ؤޤ֤ B ΰư E Ȥޤ
ȡADB + BDC + EDC = ADB + BDC + BDC = ADB + BDC * 2 = 180ʤΤǡ
ADE ƱľˤꡤAE = AD + DE = AD + DB = AD + BD = 6 cmޤ EC = BC = 4 cm Ǥ
ˡDBC = DEC = AEC ǡAD//BC PCB = ACB = CAE ʤΤǡBPC ECA Ȥʤꡤ
BPBC = ECEABP4 = 46BP = 8/3 cmˤʤޤ

졤AC = 5 cm ϻȤäƤʤ
ͥνȡ 96ڡ 12:24:34 MAIL:uchi@sco.bekkoame.ne.jp 39761
uchinyan
ǼĤɤߤޤ
Ϥ곧ñä褦Ǥ͡

#39749#39750#39751#39752#39753#39755#39756#39757#39758#39760
DB = CB Ȥʤ뤳ȤܤƲ򤯲ˡŪ˳󤳤βˡΤ褦Ǥ

#39761
BCD CD ˴ؤޤ֤ B ΰư E Ȥ BPC ECA Ȥʤ뤳Ȥ򤯲ˡ
ɡDBCE ϤҤʤǤ͡

#39759
ؤˤˡ
ͥνȡ 96ڡ 12:47:28 MAIL:uchi@sco.bekkoame.ne.jp 39762
դޤ
45ȡ345λѷͤ㤤ޤADĹ뤳ȤǻŻεٷƻ֤Dz򤱤ޤ϶路ޤŪ䤵äǤ͡
96ڡ 14:38:41 39763
mukku
󤫤Ϥ󤿤Ǥ
96ڡ 19:55:10 39764
Ԥ뤹
פ֤ĩ蘆Ƥޤ
ʤAD=2cmBC=BD=4cmޤDzä˵Ťʤäġġġ.orz
96ڡ 20:37:25 39765
ϥ饮㡼ƥ
ήβǤ񤷤ä̤˲狼ʤ
97ʶ 12:11:21 HomePage:湩ؤ˥39766
⡼ޥ
ޤɤä...^^;
ФƤʤ褦ʤΤ?...ȿͤοޤ...Ȥ......
6t/4=4t/a
a=8/3

֤ޤʤȤ狼ˤ...^^;...Orz
97ʶ 18:39:26 39767
Ф
£á£ĤФơʤȤ餤ñäȤΤ5cmϻȤʤäܤޤ
98ڡ 18:59:59 39768
ؤ
ϴñä
910ʷ 21:35:50 MAIL:shuhei.sano07@gmail.com 39769