ǯ
ȤꤢƱ礭Ȥü첽
CEĹơĹBFĹBFQP롣
DCE˿DH
CDHBCPEDHFPQ
Ĺι⤵BP=FQ=1cm
ʤΤǡ14cm2ˡ2cm⤵1cmĹä16cm2
̷ϡ줫
117ڡ 0:28:31 48515
٥륯åĥ
ˣ£ãġˣģţƣǤƱ򤯤äĤʿԻշη֤ꡢѷãģŤȹƱ̾ѷǤ褦˺2Ǥ줾ǡ2⤵2ʿԻշäƵޤ

ȣɣʣáţʣˣ̤Ȥȡ£ȡƣ̡2ʿԡ
áŤ̤äƣ£Ȥȣƣ̤ʿԤ2⤵2ʿԻշǤѤϡ142+22ˡ216ˤʤޤ
117ڡ 0:39:31 48516
鯤ο
AB=a,DE=b,CDEȤȤ

BCDa^2/2
CDE14
DEFb^2/2
BDF1/2*2a*2b*sin(+/2)abcos

CDE;Ѥơ
a^2+b^2-2abcosȡCE^24

BCEF
ᢤBCDܢCDEܢDEFBDF
1/2(a^2+b^2-2abcos)+14
16
//
117ڡ 0:34:41 48517
⡼ޥ
ͳ٤礭Τ...
E=90ü첽
14*(16/16)=16...
ޤ뤱...
ǤΤɤ=դ˷ޤΤɤ褯狼ޤǤ...^^;
鯤οͤޤβǼǤޤm(_ _)m
117ڡ 0:50:59 48518
鯤ο
ϰϤDz򤭤ޤ

CEβCHIEȤʤ褦ˡH,IȤ롣

ȡECFᢤEIDǤꡢԤԤE濴Ȥ90ž޷
顢CF=DICFIDȤʤꡢCFIDθJȤȡ
DCJľѻѷȤʤꡢDCJܢCDJ90롣
ˤꡢ
BCFܢCDI
BCDܢDCFܢCDI
BCDܢDCJܢCDJ
180
CBDC
CFDI
äơ
BCFᢤCDI
äơ
BCEF
ᢤBCFݢCEF
ᢤCDIIED
ᢢCDEI
ᢤCDEܢCEI
ᢤCDE1/2CHIJ
14+2*2/2
16
117ڡ 2:05:52 48519

ü첽ǵޤǤ˵󤬤äƤˡ⻲ͤ
ˡͤޤФ󤱤ߤǤ(^_^;)
DCE
줾C濴˺90١E濴˱90ٲžơ
BCH,FIEȡ޷ϡ
ϻѷBCEFIHȾʬ(ƱоΤο޷)ˤʤΤǡ
(14+2^2+14)/2=16cm^2

117ڡ 2:43:40 48520
Ȥ
ɸB(0,0),F(a,0),D(b,c)Ȥ
BD=sqrt(b^2+c^2),FD=sqrt((a-b)^2+c^2)
ABCD1=sqrt(b^2+c^2)/sqrt(2)
DEFG1=sqrt((a-b)^2+c^2)/sqrt(2)
B,D濴ˤ줾ABCD1դĹ
αߤθȤC((c+b)/2,(c-b)/2)
D,F濴ˤ줾DEFG1դĹ
αߤθȤE((a+b-c)/2,(c+b-a)/2)
CE^2-4=0 ǻʿ
((a+b-c)/2-(c+b)/2)^2+((c+b-a)/2-(c-b)/2)^2-4
=(a-2*c)^2/4+(2*b-a)^2/4-4
=(2*c^2-2*a*c+2*b^2-2*a*b+a^2-8)/2=0(1)
ǻͳѷBCEF=CDE+ABCDȾʬ+DEFGȾʬ-BFD
=14+(b^2+c^2)/4+((a-b)^2+c^2)/4-c*a/2
=(2*c^2-2*a*c+2*b^2-2*a*b+a^2+56)/4(1)
2*c^2-2*a*c+2*b^2-2*a*b+a^2=8Ȥ
ͳѷBCEF=(8+56)/4=16()
˭ԡ 117ڡ 4:32:10 48521
å
FCĹơB򲼤ȡCDEȹƱʻѷǤޤ
117ڡ 4:33:25 48522
ֿء׾ι
ü첽Ǥʤ줫ͤƤߤޤ
117ڡ 6:50:28 48523
algebra
ü첽ǵޤ

1/2{2(197/14)213/7}116
117ڡ 10:14:47 48524
Ф
DCE˿򤪤BCEαĹ塢ƤCEαĹȤɤɤ򲼤Ȥ˹ƱʻѷǤơʿפǤ
117ڡ 22:15:46 48525

ãŤդȤޤƷ֤ȹƱʻѷǤ롤ȤˡǤޤ

ưäƤߤΤǡФİ
https://youtu.be/rRFBt3FyOhs
118ʶ 22:07:22 MAIL:https://youtu.be/rRFBt3FyOhs 48526

ۤ󡢤㡢Ӥäꡣ
119ڡ 15:16:27 48527
̻
ФݤƱˡDz򤭤ޤ
­ʬCEĹabʬ䡢Ĺc(14)Ȥ
abcȤäơƱľѻѷ
Ѥ׻ޤ
CDE߳ѻѷξϡ­CDEγˤʤꡢ
ƱľѻѷϽФƤޤ׻Ͼ䤳Ǥ
ϡCEaEȿ­ȤεΥbȤabcȤä
׻ޤʸѤפĤޤǤ

ѷäѤȾʬȤΤû
1110 11:34:00 48528
ޤ
آ⹻ؤȥƥåץåפƤ˿ý
Ʊޤ꤬夲ƤΤǡ򤱤ޤ (^^;
somewhere in the world 1111ʷ 23:46:17 48529
ޤ
#48514 kyorofumi

ޥ뤵󡢹פƤʤǤ͡ (^^;
somewhere in the world 1111ʷ 23:48:00 48530
kyorofumi
Ǥͥ͡ߤʤΤжĺǤ

2Ĥ¤٤ưۤʤȤ߹碌ȤɤʤǤ礦
1113ʿ 1:10:29 48531
ޥ
#48529
ͥǤ˿1984ǯ4ǤȤϡ3ĤˤʤäƤǡǤϼ桢ȤȤˤʤäƤޤơιϻϻäƤʤΤǤ
MBP 1113ʿ 14:48:52 HomePage:48532
ˤ
٥ȥǤäƤޤޤߤѤǤ
Ķļˡ 1113ʿ 16:08:54 HomePage:ޤޤ48534