#include<stdio.h>main(){ float a,b,h,s; printf("a,b,h="); scanf("%f%f%f",&a,&b,&h); s=1.0/2*(a+b)*h; printf("s=%8.2f\n",s);}
#include<stdio.h>main(){ float a,b,h,s; printf("a,b,h="); scanf("%f,%f,%f",&a,&b,&h); s=1.0/2*(a+b)*h; printf("s=%8.2f\n",s);}