Inaltimea tetraedrului cade in centrul de greutate al trg cade e la intersectia medianelor la 2/3 de varf si 1/3 de baza mediana e si inaltime in trg echilateral h=l√3/2=12√3/2=6√3 Fie tetraedrul VABC in care inaltimea cade in O trg VOC e trg dreptunghic in care OC=2/3*h=2/3*6√3=4√3 VO^2=VC^2-OC^2=12^2-4^2*3=4^2*3^2-4^2*3=4^2(9-1)=4^2*8 VO=√4^2*8=4√8=4√2^2*2=8√2
