Question

Un paralelipiped dreptunghic are diagonalele de 9 si 12 si h=5 radical din 3. Sa se afle latura.

Answer 1

AC intersectat DB ={O}
AO=OC=AC/2=12/2=6
DO=OB=BD/2=9/2=4,5

fie ΔABD, DN_|_AB
DN-h
DN=5√3
A ΔABD=b*h/2= AO*DB/2=  6*9/2=  3*9=27

A ΔABD=b*h/2= DN*AB/2= 5√3*AB/2

5√3*AB/2= 27
AB=2*27/5√3   rationalizam

AB=2*27√3/5*3
AB=2*9√3/5
AB=18√3/5