Răspunsuri

2014-04-15T13:16:51+03:00
A=√(p-a)(p-b)(p-c)   √lung
p=a+b+c/2=9+12+15/2=36/2=18
A=√(18-9)(18-12)(18-15)=
=√3² *3*2*3=3*3√2=9√2