Java三角形类继承Shape

package com.itheima;
public class Triangle extends Shape {
    private int a;
    private int b;
    private int c;
    public Triangle() {

    }
    public Triangle(int aa,int bb,int cc)
    {
        this.a=aa;
        this.b=bb;
        this.c=cc;
    }
    @Override
    public double getArea()
    {   int p;
        double s;
        p=(this.a+this.b+this.c)/2;
        s=Math.sqrt(p*(p-this.a)*(p-this.b)*(p-this.c));
        return s;
    }
    public static void main(String []args)
    {
        Triangle t1=new Triangle(3,4,5);
        System.out.println("三角形的面积是"+t1.getArea());
    }

}