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200 4年高考数学试题 (必修 +选修Ⅱ )第 ( 2 0 )题是这样的 :如图 1,已知四棱锥P—ABCD ,PB⊥AD ,侧面PAD为边长等于 2的正三角形 ,底面ABCD为菱形 ,侧面PAD与底面ABCD所成的二面角为12 0° .(Ⅰ )求点P到平面ABCD的距离 ;(Ⅱ )求面APB与面CPB所成的二面角的大小 .高考结束后
In the 200th college entrance examination mathematics question (required + elective II) the (20) question is this: As shown in Figure 1, the known quadrilateral pyramid P-ABCD, PB⊥AD, the side PAD is an equilateral triangle with side length equal to 2, and the bottom ABCD is a rhombus. The dihedral angle formed by the side PAD and the bottom ABCD is 12 0°. (I) The distance from the point P to the plane ABCD; (II) The size of the dihedral angle formed by the plane APB and the plane CPB. After the college entrance examination