C=C_(1)+[b]2[/b]*C_(2)
R=[green][b]2[/b][/green]
C_(1)=(1/2)*2π*R=(1/2)*2π*[green][b]2[/b][/green]=2π
r=[red][b]1[/b][/red]
C_(2)=(1/2)*2π*r=(1/2)*2π*[red][b]1[/b][/red]=π
C=2π+[b]2[/b]*π=4π
б)
S=S_(1)+2S_(2)
S_(1)=(1/2)π*R^2=(1/2)*π*2^2=2π
S_(2)=(1/2)π*r^2=(1/2)*π*1^2=(1/2)*π
S=2π+2*(1/2)π=3π