(1)
过D作DE//PM交AB于E
AE/AB=DC/CB=1/2
AM/AE=AP/AD=2/3
故AM/AB=1/2*2/3=1/3
(2)
过D作DE//PM交AB于E
过D作DE//PN交AC于F
AE/AB=DC/CB=1/2
AM/AE=AP/AD
故AM/AB=AP/2AD
同理AN/AC=AP/2AD
故AM/AB =AN/AC
(1)
过D作DE//PM交AB于E
AE/AB=DC/CB=1/2
AM/AE=AP/AD=2/3
故AM/AB=1/2*2/3=1/3
(2)
过D作DE//PM交AB于E
过D作DE//PN交AC于F
AE/AB=DC/CB=1/2
AM/AE=AP/AD
故AM/AB=AP/2AD
同理AN/AC=AP/2AD
故AM/AB =AN/AC