#difine pai 3.14159
main()
{
float radius=0.0;
float circle=0.0;
float area=0.0;
printf("please input radius :")
scanf("%f",&radius);
circle=2*pai*radius;
area=pai*radius*radius;
printf("circle is ");
printf("%f",circle)
printf("area is ");
printf("%f",area);
}
呵呵,好久不写C了,连TURBEC 都删了,你调试一下,看看对吗