题目如图,△ABC\triangle ABC△ABC内接于⊙O\odot O⊙O,ABABAB是直径.BC=4BC=4BC=4,AC=3AC=3AC=3,CDCDCD平分∠ACB\angle ACB∠ACB,则弦BDBDBD的长为______.知识点：勾股定理的性质章节：图形的性质 / 三角形
如图,内接于,是直径.,,平分,则弦的长为______.如图,内接于,是直径.,,平分,则弦的长为______.如图,内接于,是直径.,,平分,则弦的长为______.