Răspunsuri

2014-05-21T01:10:23+03:00
Se ia trapezul dreptunghic OBB'O' 
ducem din B' perpendiculara pe OB si notam cu N

NB=OB-O'B'=11-5=6
ΔB'NB, mas<N=90   ⇒BB'²= NB²+B'N²= 6²+8²=36+64=100   ⇒BB'=10
g=BB'=10

Al=πg (R+r)= 10π( 11+5)= 10*16π= 160π

V=πh (R²+r²+Rr)/3=   8π (11²+5²+5*11)/3=  8π (121+25+55)/3= 8π *201/3=8* 67π=536π