题解 | #计算三角形的周长和面积#

#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;

int main()
{
    float a=0;
    float b=0;
    float c=0;
    cin>>a>>b>>c;
    float C=a+b+c;
    float p=(C)/2;
    float S=sqrt(p*(p-a)*(p-b)*(p-c));
    cout<<fixed<<setprecision(2)<<
        "circumference="<<C<<" "<<
        "area="<<S<<endl;
    return 0;
}