海伦公式
计算三角形的周长和面积
http://www.nowcoder.com/questionTerminal/109a44d649a142d483314e8a57e2c710
海伦公式
import java.util.*; public class Main { public static void main(String[] args){ Scanner sc = new Scanner(System.in); double a = sc.nextDouble(), b = sc.nextDouble(), c = sc.nextDouble(); double zh = a + b + c; double p = zh/2; System.out.printf("circumference=%.2f area=%.2f", zh, Math.sqrt(p*(p - a)*(p - b)*(p - c))); } }