题解 | #计算三角形的周长和面积#

/**
 * 海伦公式求面积：
 * p = (a + b + c)/2
 * area = sqrt(p*(p-a)*(p-b)*(p-c))
 */
let [a, b, c] = readline().split(" ").map(Number);
let cir = a + b + c;
let p = cir / 2;
let area = Math.sqrt(p * (p - a) * (p - b) * (p - c));
console.info("circumference=" + cir.toFixed(2) + " area=" + area.toFixed(2));