#include <stdio.h> #include<math.h> int main() { float a,b,c,circumference,area,cosC,sinC; scanf("%f %f %f",&a,&b,&c); circumference=a+b+c; cosC=(a*a+b*b-c*c)/(2*a*b); sinC=sqrt(1-cosC*cosC); area=a*b*sinC/2; printf("circumference=%.2f area=%.2f",circumfer...