设 AB = AC = 2x ,BC = y ,则 AD = BD = x .
以下分两种情况讨论:
①
若 AC+AD = 12 ,BC+BD = 9 ;
即有:2x+x = 12 ,y+x = 9 ,
解得:x = 4 ,y = 5 ,
可得:AB = AC = 8cm ,BC = 5cm .
②
若 AC+AD = 9 ,BC+BD = 12 ;
即有:2x+x = 9 ,y+x = 12 ,
解得:x = 3 ,y = 9 ,
可得:AB = AC = 6cm ,BC = 9cm .
设 AB = AC = 2x ,BC = y ,则 AD = BD = x .
以下分两种情况讨论:
①
若 AC+AD = 12 ,BC+BD = 9 ;
即有:2x+x = 12 ,y+x = 9 ,
解得:x = 4 ,y = 5 ,
可得:AB = AC = 8cm ,BC = 5cm .
②
若 AC+AD = 9 ,BC+BD = 12 ;
即有:2x+x = 9 ,y+x = 12 ,
解得:x = 3 ,y = 9 ,
可得:AB = AC = 6cm ,BC = 9cm .