Răspunsuri

2014-08-22T18:55:41+03:00
L-lungimea
l-latimea
A=l.L=20
P=2(L+l)=18 ; L+l=9
cu Pitagora daca notam cu d diagonala
d²=L²+l²=(L+l)²-2L.l
d²=81-2.20=81-40=41
d=√41