R=l*sin(alpha/2)
S=S1+S2
S1=pi*R^2
S2=S1*l/R=pi*R*l
S=pi*R*(R+l)=pi*l*sin(alpha/2)*(l*sin(alpha/2)+l)=pi*l^2*sin(alpha/2)*(sin(alpha/2)+1)=
=pi*12^2*sin(pi/6)*(sin(pi/6)+1) см^2 =108*pi см^2 =<span>
339,292
</span>см^2 ~ 339,3
см^2
1)960÷4=240(р) 960 больше 4
2)12000÷240=50(м)на 12000рублей
<span>7/15+5/6=14/30+25/30=39/30=13/10=1.3
</span><span>2 4/ 15+4 11/12-3 9/20 = 2 16/60+4 55/60- 3 27/60= 3 8/10= 3,8</span>