c语言基本运算训练

1.求三角形面积

#include
#include
int main()
{
	double a,b,c,s,area;
	a=3.67;
	b=5.43;
	c=6.21;
	s=(a+b+c)/2;
	area=sqrt(s*(s-a)*(s-b)*(s-c));
	printf("a=%ftb=%ftc=%ft");
	printf("area=%fn");
	return 0;
 } 

运行结果

a=0.000000      b=0.000000      c=-1.#QNAN0     area=0.000000

--------------------------------
Process exited after 0.0094 seconds with return value 0
请按任意键继续. . .

2.输入球半径，求球体积

#include
#include
#define PI 3.14
int main()
{
	float r,v;
	printf("请输入半径r：");
	scanf("%f",&r);
	v=4*PI*pow(r,3)/3;
	printf("%f",v);
	return 0; 
 } 

运行结果

请输入半径r：3
113.040001
--------------------------------
Process exited after 3.564 seconds with return value 0
请按任意键继续. . .

3.字母的大写转小写

#include
int main()
{
	char c1,c2;
	c1='A';
	c2=c1+32;
	printf("%c,%cn",c1,c2);
	printf("%d,%dn",c1,c2);
	return 0; 
}

运行结果

A,a
65,97

--------------------------------
Process exited after 0.01597 seconds with return value 0
请按任意键继续. . .