1) Patrat: d=l√2=6√2⇒l=6, dar l=R√2,deci R√2=6⇒R=3√2
Truinghi echilateral: a=R/2=3√2/2
2)A=l²⇔l²=16⇒l=4.Atunci: R√2=4⇒R=2√2
a)A=πR²=π(2√2)²=8π
b)L=2πR=4√2π
c)A=Asector-A ΔOBC=2π-4, unde
A sector =Acerc/4=2Ï€
A ΔOBC=Apatrat/4=4