#include <stdio.h> #include<math.h> float thetich(float a)//chuong trinh tinh the tich khoi cau { 	return (a=4*M_PI*pow(a,3)/3); }  main() { 	float r,v;	//r: ban kinh v: the tich 	printf("ban kinh hinh cau la: R="); 	scanf("%f",&r); 	while(r<0) // kiem tra xem ban kinh co duong khong 	{ 		printf("ban kinh phai khong am!\nhay nhap lai: R="); 		scanf("%f",&r); 	} 	v=4*M_PI*r*r*r/3; 	printf("the tich cua khoi cau la:V=%.2f\n",v); 	printf("the tich cua khoi cau la:V=%.2f",thetich(r)); }