Avem:
(axb)/2=15 cm^2, "^"= la patrat
V(a^2+b^2)=V61 cm, "V"=radical
axb=30
a^2+b^2=61
axb=30
(a+b)^2 -2axb=61
(a+b)^2 -2x30=61
(a+b)^2=121
a+b=11
Avem a+b=11 si axb=30, deci putem forma ecuatia de gradul 2:
t^2 -(a+b)t +axb=0
t^2 -11t +30=0
(t-6)(t-5)=0
t=5 sau t=6
Deci a=5cm si b=6cm sau a=6cm si b=5cm
Concluzie catetele au 5 si 6 cm.
