• 2022-07-01
    已知环形截面外径为D,内径为d,则截面对形心的极惯性矩( )
    A: [img=124x69]18038afc5ce4238.png[/img]
    B: [img=132x73]18038afc68b92d5.png[/img]
    C: [img=120x66]18038afc736fc56.png[/img]
    D: [img=125x70]18038afc7dafae5.png[/img]