// 継承によって，メソッドの返値型を統一サンプル

import java.lang.Math;

class Takakkei {

    public double syuui(){
        return 0.0;
    }

    public double menseki(){
        return 0.0;
    }
}

class TyokakuSannkakkei extends Takakkei{

    private double a;
    private double b;

    public TyokakuSannkakkei (double xa, double xb){
        a = xa;
        b = xb;
    }
    public String toString(){
        return  "この直角三角形の直角を挟む辺は，" +  a + ", " + b;
    }

    public double mawari(){
        return a+b+(double)Math.sqrt(a*a+b*b);
    }

    public double menseki(){
        return (a*b)/2;
    }
}

class Tyouhoukei  extends Takakkei{

    private float a;
    private float b;

    public Tyouhoukei (float xa, float xb){
        a = xa;
        b = xb;
    }

    public String toString(){
        return "この長方形の辺は " + a + ", " + b;
    }

    public double syuui(){
        return (a+b)*2;
    }

    public double menseki(){ // public float menseki() だとコンパイルエラー
        return a*b;
    }
}

public class xExtd01 {
    public static void main(String xargs[]){

        TyokakuSannkakkei tyosan  = new TyokakuSannkakkei(3.0, 4.0);
        Tyouhoukei        tyou    = new Tyouhoukei(6.0f, 7.0f);

        System.out.print(tyosan);
        System.out.print  (" 周囲：" + tyosan.mawari());
        System.out.println(" 面積：" + tyosan.menseki());

        System.out.print(tyou);
        System.out.print  (" 周囲：" + tyou.syuui());
        System.out.println(" 面積：" + tyou.menseki());
    }
}