| 仭No40303偵曉怣(偄傇偝傫偺婰帠) > > 偳側偨偐偍婅偄偟傑偡丅 > 嵗昗嬻娫偵5揰A(1乯B(2,1,4乯C(3,2,2乯D(2,7,1乯E(3,4,3乯偑偁傞丅 > > (1)慄暘AB偲慄暘AC偺側偡妏傪兤偲偡傞偲偒sin兤偺抣傪媮傔傛丅乮0亱<兤<180亱乯 > (2)揰E傪捠傝嶰妏宍ABC傪娷傓暯柺偵暯峴側暯柺傪兛偡傞丅巐柺懱ABCD傪暯柺兛偱愗偭偨帪偺愗傝岥偺柺愊傪媮傔傛丅 > > 摎偊乮侾乯併21/5偼乮俀乯偼8併21/49偱偡丅
(2) AD,BD,CD 偲暯柺兛偲偺岎揰傪偦傟偧傟 P,Q,R 偲偍偔丅 暯柺兛忋偺揰偼 仾AE+x仾AB+y仾AC 偱昞偝傟傞偺偱 仾AP亖k仾AD 偲偍偗偽丄仾AE+x仾AB+y仾AC亖k仾AD 傛傝 k偺抣偑弌傞丅 偙傟偐傜仮ABC偲仮PQR偺憡帡斾偑傢偐傝傑偡丅
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