正方形ABCD中,对角线AC=24,P为AB边上一动点,则点P到对角线AC、BD的距离之和为_.

问题描述:

正方形ABCD中,对角线AC=24,P为AB边上一动点,则点P到对角线AC、BD的距离之和为______.

如图,
∵PE⊥AC,BD⊥AC
∴PE∥BO,
∴△APE∽△ABO,
∴则

PE
BO
=
AP
AB

同理可证:
PF
AO
=
BP
AB

AP
AB
+
BP
AB
=
PE
BO
+
PF
AO
=
AB
AB
=1,
∵AO=BO,
∴PE+PF=AO=BO,
∵AC=24,
∴AO=12,
故PE+PF=12.
故答案为:12.