Răspuns :

a |__a___||__a___||__a___|
b |__a___|........258..........|

Se observa ca 2 segmente=258
Aflam cat inseamna un segment
258:2=129

a=129x3=387
b=129
a ori 3-a=258
a ori 2 =258
a=258/2
a=129