java练习题5.19

import java.util.Scanner;
public class ki {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Scanner input=new Scanner(System.in);
double a=input.nextDouble();
double b=input.nextDouble();
double c=input.nextDouble();
if(isValid(a,b,c)==true)
{
System.out.print("这三边可以构成三角形，此三角形的面积是："+area(a,b,c));
}
else
System.out.print("此三边不可以构成三角形。");
}
public static boolean isValid(double side1,double side2,double side3){
if(side1+side2>side3&&side1+side3>side2&&side2+side3>side1)
return true;
else
return false;
}
public static double area(double side1,double side2,double side3){
double p;
p=(side1+side2+side3)/2;
double area;
area=Math.sqrt(p*(p-side1)*(p-side2)*(p-side3));
return area;
}
}