a)
notam VABC tetraedrul
ducem VM _I_ BC
L=latura=BC=6√3
Aunei fete=L² x √3/4=(6√3)² x√3/4=108x√3/4=27√3 cm²
A t= 4x27√3=108√3 cm²
b)
notam VABC piramida
ducem VM _I_ BC
Abazei=16√3 cm²
L² x√3 /4 = 16√3
L² /4=16
L² =64
L=8 cm
VBC isoscel
BC=8
BM=8/2=4
tg 30 =VM/BM=√3/3
VM/4=√3/3
VM=4√3/3
Atriunghiului VBC=[ 8x4√3/3]/2=16√3/3 cm²