case 6:
        b=sqrt(6*6+9*9);
        printf("%f",b);
        break;
        
        case 8:
        c=2*pi*5.;s=pi*25.;v=4*pi*125./3;
        printf("%f\n%f\n%f",c,s,v);
        break;
        
        case 11:
        float d=100/3.0;
        printf("%f",d);
        break;