题解 | #计算三角形的周长和面积#

#include<bits/stdc++.h>
using namespace std;
int main()
{
    double a,b,c;
    cin>>a>>b>>c;
    double C=(a+b+c)/2;
    double S=sqrt(C*(C-a)*(C-b)*(C-c));
    cout<<"circumference="<<fixed<<setprecision(2)<<C*2<<" "<<"area="<<fixed<<setprecision(2)<<S<<endl;
}