Răspuns:
B=pi/4=180/4=45°
C=pi/6=180/6=30°
ducem ad perpendicular bc
triunghiul abd isoscel
ab^2=ad^2+bd^2
ad=bd=radical 36/2=radical18=radical 2
in triunghiul adc
sin c=sin 30°=1/2
ad/ac=1/2
3radical 2/ac=1/2
ac=radical 2
cos c=cos30°=radical 3/2
dc/ac=radical 3/2
dc/6radical 2=radical 3/2
dc=3radical 6
bc=3radical 2+3radical 6
P=6+6radical2+3radical2+3radical6=6+9radical2+3radical6=3(2+3radical2+radical6)
