Thread: illegal break?!?!?

i am working on homework for my programming class which uses C. i have to make a program that calculates some simple geometry. the user chooses which shape to make calculations on. i am using a switch statement but when i try to break, it comes up as illlegal break when i compile. can anyone help? this is just part of the program

Code:

switch(shape)
	case 1:
		printf("Enter the radius of a circle(9999 to quit):\n");
		scanf("%lf", &radius);

		while(radius != 9999){
			while(radius < 0){
				printf("Invalid input!\n");
				printf("Enter the radius of a circle(9999 to quit):\n");
				scanf("%lf", &radius);
				}
			area = radius * radius * PI;
			circumference = 2 * radius * PI;
			printf("The area of the circle is %.2lf\nThe circumference of the circle is %.2lf\n", area, circumference);

			printf("Enter the radius of a circle(9999 to quit):\n");
			scanf("%lf", &radius);
			}
		break;

	case 2:

lol something so simple
thanks