7.【解】 (1)因为∠CPD=90°,∠APB =45°,所以∠APC +∠BPD=90° -45° =45°.因为∠APC =30°,所以∠BPD =45° -30°=15°因为PM平分∠APC,PN平分∠BPD,所以∠ A P M = ( 1 )/ ( 2 ) ∠ A P C = 1 5 ^ ( ° ),∠ B P N = ( 1 )/ ( 2 ) ∠ B P D = 7 . 5...