过D作AB的垂线交AB于E由题目可得DE=3.8cm∵∠C=90°∠CAB=60°∴∠B=30°∵AD平分∠CAB又∵∠CAB=60°∴∠DAB=30°=∠B∵DE⊥AB∴E点平分AB即AB=2 BE∵DE⊥AB,∠B=30°BE=根号3 倍的DE∴AB=2根号3 倍的DE∵∠C=90°,...