Question

P为线段AC的中点,M为线段AB的中点,N为线段BC的中点.MN=PC,MP=AP-PB的差除以二,为什么对,急

Answer 1

回答MP=AP-AM=1/2(AC-AB)

CN=1/2BC=1/2(CA-CB)

即MP=CN

即MP+PB+BN=PB+BN+CN

即MN=PC

2 MP=1/2(AC-AB)

=1/2AC-1/2AB

=AP-AM

=AP-1/2AB

=AP-1/2(AP+PB)

=AP-1/2AP-1/2BP

=1/2AP-1/2BP

=1/2(AP-PB)