过F分别作AB、AD的垂线,垂足分别为M、N显然,AMFN是正方形∴ AM=AN=FM=FN∴ AF=√2·FM=√2·FN又BE平分∠ABC,AC⊥BC∴ FC=FM∴ AF=√2·FC∴ AC=(1+√2)FC∴ FC=(√2-1)AC∴ FN=FC=(√2-1)AC∴ EF:EB=FN:AB=(√2-1)AC:√2AC=(√2-1):√2∴ EF:FB=(√2-1):[√2-(√2-1)]=(√2-1):1