如图,在四棱锥P-ABCD中,底面ABCD为菱形,∠BAD=60°,Q为AD的中点,PA=PD=AD=2
(1)点M在线段PC上,PM=tPC,试确定t的值,使PA∥平面MQB;
(2)在(1)的条件下,若平面PAD⊥平面ABCD,求二面角M-BQ-C的大小.
考点分析:
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