Question

已知线段cd延长cd到b是bd等于二分之一cd再反向延长cd到a使ac=cd

已知线段cd 延长cd到b,使BD=1/2CD,在反向延长CD到A,使AC=2DB,若AB=8cm,求出CD与AD的长.

Answer 1

∵BD=1/2CD
AC=2BD
∴AC=2×1/2CD=CD
∵AB=AC+CD+BD=CD+CD+1/2CD=5/2CD
∴CD=2/5AB=2/5×8=16/5=3.2
∴AD=AC+CD=2CD=2×3.2=6.4