连接CP
∵∠ACB=90,AC=6,BC=8
∴S△ABC=AC×BC/2=6×8/2=24
∵PM⊥AC,PN⊥BC
∴S△APC=AC×PM/2=6×PM/2=3PM,S△BPC=BC×PN/2=8×PN/2=4PN
∴S△ABC=S△APC+ S△BPC
∴3PM+4PN=24
∵PM=PN
∴7PM=24
∴PM=24/7
连接CP
∵∠ACB=90,AC=6,BC=8
∴S△ABC=AC×BC/2=6×8/2=24
∵PM⊥AC,PN⊥BC
∴S△APC=AC×PM/2=6×PM/2=3PM,S△BPC=BC×PN/2=8×PN/2=4PN
∴S△ABC=S△APC+ S△BPC
∴3PM+4PN=24
∵PM=PN
∴7PM=24
∴PM=24/7