证明:延长AB至E使BE=BD∵AC=AB+BD∴AE=AC又∵锋扰AD是∠BAC的平银段分线,∴∠BAD=∠DACAD是公共边∴△ADE≌△ADC∴∠AED=∠C又∵BE=BD∴∠AED=∠BDE由三角形性质可知∠ABC=∠BDE+∠AED∴∠银搏旦ABC=2∠C得证!