cu pitagora in tr. VEC, EC=√(VC^2 - VE^2)=√(12^2 - 3 x 36)
EC=6 cm
DC=12 cm
aria bazei Ab=DC^2=144 cm2
aria laterala Al=4 x DC x VE/2=4 x 12 x 6√3/2
Al=144√3 cm2
aria totala At=Ab+Al=144+144√3
At=144(1+√3) cm2
inaltimea piramidei cu pitagora in tr. VOE, VO=√(VE^2 - OE^2)=√(3 x 36 - 36)
VO=6√2 cm
volumul piramidei
V=Sb x VO/3=144 x 6√2/3=288√2 cm3, ∡OCV=45°
sin(∡(VC;(ABCD))=sin(∡OCV)=VO/VC=6√2/12=√2/2