14.
AB+BC+CD+DF=15(AF)
AB=2; si AB =CE=2;(asta inseamna congruent ambele sunt egale ca lungime)
BC=CD si CD=CE+ED;
ED=DF;
deci AB+BC+CE+ED+DF=15
2+BC+2+2*ED=15
4+BC+2*ED=15
BC+2*ED=11;11=5+6 deci 11=5+3+3;
deci BC=CD=5 si ED=DF=3 asta inseamna ca daca inlocuim
AB+BC+CD+DF=15 =>2+5+5+3=15 (este adevarat)
15.AB+BC+CE+EF=18(AF=18) si CE=1+BC si AB=BC;CE=EF;
AB+AB+CE+CE=18 deci 2*AB+2*BC+2=18
2*AB+2*BC=16 si 16=8+8=2*4+2*4;
AB=BC=4 deci si CE=ED=5
