題目:計算各種圖形的周長和面積(圓,平行四邊形,長方形,梯形)
package com.a4_22;
/**
* Created by HongWeiPC on 2017/5/2.
*/
public interface Calculate {
double area();
double perimeter();
void show();
}
class Circle implements Calculate {
private int r;
public Circle(int r){
this.r=r;
}
@Override
public double area() {
return Math.PI * r * r;
}
@Override
public double perimeter() {
return 2 * Math.PI * r;
}
@Override
public void show() {
System.out.println("圓面積是"+this.area());
System.out.println("圓周長是"+this.perimeter());
}
}
class Parallelogram implements Calculate {
private int a, h, b; //a是底邊,b是斜邊,h是高
public Parallelogram(int a, int b, int h) {
this.a = a;
this.b = b;
this.h = h;
}
@Override
public double area() {
return a * h;
}
@Override
public double perimeter() {
return 2 * (a + b);
}
public void show() {
System.out.println("\n平行四邊形面積是"+this.area());
System.out.println("平行四邊形周長是"+this.perimeter());
}
}
class Rectangle implements Calculate {
private double a, b;
public Rectangle(double a,double b){
this.a=a;
this.b=b;
}
@Override
public double area() {
return a * b;
}
@Override
public double perimeter() {
return 2 * (a + b);
}
@Override
public void show() {
System.out.println("\n矩形面積是"+this.area());
System.out.println("矩形周長是"+this.perimeter());
}
}
class Trapezoid implements Calculate {
private double ul, dl, h; //ul是上邊長,dl是下邊長,h是高
private double x1,x2; //x1是斜邊1,x2是斜邊2
public Trapezoid(double ul,double dl,double h,double x1,double x2){
this.ul=ul; this.dl=dl; this.h=h; this.x1=x1; this.x2=x2;
}
@Override
public double area() {
return ((ul + dl) * h) / 2;
}
@Override
public double perimeter() {
return ul+dl+h+x1+x2;
}
public void show() {
System.out.println("\n梯形面積是"+this.area());
System.out.println("梯形周長是"+this.perimeter());
}
}
class TestCalculate{
public static void main(String[] args) {
Circle c1 = new Circle(5);
Parallelogram p1 = new Parallelogram(3,4,6);
Rectangle r1=new Rectangle(2,3);
Trapezoid t1=new Trapezoid(3,5,2,3,4);
c1.show();
p1.show();
r1.show();
t1.show();
}
}
運行圖