Răspuns:
Explicație pas cu pas:
a) In ΔVOM VM⊥BC VM²=VO²+OM²=12²+(10/2)²=144+2169
VM=13 cm
Avbc=VMxBC/2=13x10/2=65cm²
b)Avab=VOxAB/2=12x10/2=60 cm²
c)OB=BD/2=10√2/2=5√2 cm
tg∡VBD=VO/OB=12/5√2=12√2/10=6√2/5
d)ducem OO⊥VM scriem Avom in 2 moduri OM=AB:2=5cm
Avom=VOxOM/2=12x5/2=30 cm²
Avom=OO'xVM/2 30=OO'x13/2 OO'=60/13≅4,61 cm
e)sin∡VBO=VO/VB
VB²=OB²+VO²=(5√2)²+12²=50+144=194 VB=≅13,92 cm
sin∡VBO=12/13,92=0,86