Răspuns:
Explicație pas cu pas:
a) coarda= 2*12*cos(60/2)=12
b) 2*12*cos(120/2)=2*12*r3/2=12r3
c) ????????????
d)A = (coarda*inaltimea)/2=36r3
coarda este 2*12*sin(a/2)
Inaltimea este 12*cos(a/2)
12*12*sin(a/2)*cos(a/2)=36r3 sin(a/2)*cos(a/2)=0.5*sin(a)
sin(a) =36r3/(0.5*12*12)=r3/2 =>a=60gr, ??????