piramida triunghiulara regulata= tetraedru regulat = figura are toate muchiile congruente, adica egale
A totala= l²√3 = (12√3)²·√3 = 12²·3·√3 = 144·3·√3 = 432√3 cm²
Volumul= l³√2 / 12 = (12√3)³·√2 /12 = 432·12√3·√2 /12 = 5184√3·√2 /12 = 5184·√6/12 = 432√6 cm³
