A problem in the senior high school entrance examination in mathematics
If AB=CD is the condition, it will be easier. AB/BC = BC/CD = & gt； AM/MN=MN/NO AB=CD Draw auxiliary lines to know AM=NO because Mn 2 = AM * NO = AM 2 = ON 2 to get am=mn=no because oa=6, so on=2 to get k= 16/3.