Răspuns:
1.AB^2+AC^2=BC2
DE^2=EF^2-DF^2
2. BC^2=12^2+9^2=144+81
BC=15
EF^2=16^2+12^2=400
EF=20
HI^2=25^2-7^2=576
HI=24
RQ^2=25*10-13^2=81
RQ=9