题解 | #计算三角形的周长和面积#

#include <iostream>
#include <cmath>
#include <iomanip>

int main() {
    double a, b, c;
    std::cin >> a >> b >> c;

    double circumference = a + b + c;

    double s = circumference / 2;
    double area = std::sqrt(s * (s - a) * (s - b) * (s - c));

    std::cout << std::fixed << std::setprecision(2) << "circumference=" << circumference << " area=" << area << std::endl;

    return 0;
}