题型:问答题 已知四棱锥P-ABCD,它的底面是边长为a的菱形,且∠ABC=120°,PC⊥平面ABCD,又PC=a,E为PA的中点。(1)求证:平面EBD⊥平面ABCD;(2)求点E到平面PBC的距离;(3)求二面角A-BE-D的大小。 查看答案
题型:问答题 Project (75) .Management:includes the processes required to ensure that the project includes au the word required, and only the work required, to complete the project successfully.A.IntegrationB.ConfigurationC.ScopeD.Requirement 查看答案