package ch01_5;
public class Triangle {
	public static void main(String[] args) {
		double a,b,c,x,s ;
		a=3;
		b=4;
		c=5;
		x=(a+b+c)/2.0;
		s=Math.sqrt(x*(x-a)*(x-b)*(x-c));
		System.out.println("Ãæ»ýÎª£º"+s); 
	}
}