Question

Aria bazei piramidei regulate VABCD este egala cu 144cm2,iar iar inaltimea VO=8 cm (VM apotema).Aflati a)Aria laterala a piramidei ;b)Aria totala a piramidei ;c)Volumul piramidei Dupa dessenul dat:

Answer 1

L=12 cm
OM=L/2=6 cm
VM=rad(144+36)=rad(180)=rad(9*4*5)=6rad5 cm T.Pit. in VOM-dr in O
A(VBC)=BC*VM/2
a) Alat = 4A(VBC)=2BC*VM= 2*12* 6rad5 = 144rad5 cmp
b)Atot=Alat+Ab=144rad5 + 144 = 144(1+rad5) cmp
c) V= Ab*VO/3= 144*8(1+rad5) /3 = 48*8(1+rad5) = 384(1+rad5) cmc