import java.io.*;
public class luassegitiga
{
public static void main(String[]args)throws IOException
{
int i=1;
do
{

double alas;
double tinggi;
double luas;
BufferedReader br;
br=new BufferedReader (new InputStreamReader(System.in));
System.out.println ("masukkan alas= ");
alas=Double.parseDouble(br.readLine());
System.out.println ("masukkan tinggi= ");
tinggi=Double.parseDouble(br.readLine());
luas=0.5*alas*tinggi;
System.out.println("luas segitiga= "+luas);
i++;
}
while(i<4);
}
}