C语言,求三角形面积:从键盘输入三个顶点坐标(x1,y1)(x2,y2)(x3,y3...答:dy;dx=x1-x2;dy=y1-y2;return sqrt(dx*dx+dy*dy);}int main(){float x1,x2,x3,y1,y2,y3,p,s,a,b,c;scanf("%f %f",&x1,&y1);scanf("%f %f",&x2,&y2);scanf("%f %f",&x3,&y3);a=dis(x1,y1,
我写的C语言——用海伦公式求三角形面积,为什么不对?答:三角形半周长一定大于每条边。所以中间一步判断正负的可以省掉。其实应该加上这样一步判断:include<stdio.h> include<math.h> void main(){float a,b,c,s,area,x;printf("Please input three numbers:");scanf("%f,%f,%f",&a,&b,&c);if ((a+b>c) && (a+c>b) && (b+c>a)) ...
C语言:平面上有三个点A、B、C,求∠ABC的大小。答:void main(){ float x1,y1,x2,y2,x3,y3;float a,b,c,t;printf("请输入6个实数:");//A(x1,y1),B(x2,y2),C(x3,y3)scanf("%f,%f,%f,%f,%f,%f,%f",&x1,&y1,&x2,&y2,&x3,&y3);c=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));b=sqrt((x1-x3)*(x1-x3)+(...