Răspuns:
Explicație pas cu pas:
AB=18√2 ΔVOB este dreptunghic isoscel
VO=OB OB=BD/2 BD=AB√2=18√2√2=18×2=36
VO=36/2=18
OP⊥BC OP=AB/2=9√2
In ΔVOP VO²+OP²=VP²=Apotema
36²+81×2=1458 VP=38,18
a)V=Ab×h/3= 18²×2×18=11664 cm³
At=Al+Ab= (P×VP)/2+Ab=(4×18√2+38,18)2+648=(4×25,38 +38,18)/2+648=139,7/2+648=69,95+648=717.85 cm²
b)tg∠VPO=18/OP=18/9√2=√2
c) AΔDMB min inseamna ΔDMB ECHILATERAL CU LAT BD=36
MO=l√3/2=36√3/2=18√2
UNGH DIEDRU ESTE ∠MOC OC⊥BD OM⊥VC cos∠MOC=OC/MO=18/18√2=√2/2
