- 問題詳情:已知PABC是正三棱錐,其外接球O的表面積爲16π,且∠APO=∠BPO=∠CPO=30°,則三棱錐的體積爲 .【回答】【解析】設球的半徑爲R,△ABC的外接圓圓心爲O′,則由球的表面積爲16π,可知4πR2=16π,所以R=2.設△ABC的邊長爲2a,因爲∠APO=∠BPO=∠CPO=30°,OB=OP=2,所以BO′=R=,OO′==1,PO′=OO′...
- 26069
- 問題詳情:Aftertheirofficialtalks,thetwocountriesagreedto apositive,cooperative,andcomprehensiveChina-USrelationshipforthe21stcentury. A.buildup B.putup C.takeup D.breakup【回答】A知識點:動詞題型:選擇題...
- 21178
- Theclinicalsignificanceoftestingapo1andapo100levelsinpatientswithchronichepatitisRelationshipofApolipoproteinMwithOther(apo)LipoproteinsinCoronaryArteryDiseasePatients;ObjectiveToinvestigatetherelationshipbetweenapolipoproteins(apo)A1,Bandgallstonefo...
- 19769
- 問題詳情:.如圖,PA是⊙O的切線,切點爲A,OP=4,∠APO=30°,則⊙O的半徑爲( )A.1 B. C.2 D.4 【回答】C知識點:點和圓、直線和圓的位置關係題型:選擇題...
- 5754
- 問題詳情:如圖,PA是⊙O的切線,切點爲A,∠APO=36º,則∠AOP=( )A.54º B.64º C.44º D.36º【回答】A知識點:點和圓、直線和圓的位置關係題型:選擇題...
- 14800