1、1.5和1，颜色为yellow，filled为true的Triangle
对象，然后显示它的面积、周长、颜色以及是否被填充。 public class Exercise11_1 {
public static void main(String[] args) {
Triangle triangle = new Triangle(1, 1.5, 1); triangle.setColor(\ triangle.setFilled(true);
System.out.println(triangle);
System.out.println(\ + triangle.getArea());
System.out.println(\ + triangle.getPerimeter()); System.out.println(triangle); } }
class Triangle extends GeometricObject {
private double side1 = 1.0, side2 = 1.0, side3 = 1.0; public Triangle() { }
public Triangle(double side1, double side2, double side3) { this.side1 = side1; this.side2 = side2; this.side3 = side3; }
/** Implement the abstract method findArea in GeometricObject */ public double getArea() {
double s = (side1 + side2 + side3) / 2;
return Math.sqrt(s * (s - side1) * (s - side2) * (s - side3)); }
/** Implement the abstract method findCircumference in * GeometricObject **/
public double getPerimeter() { return side1 + side2 + side3; }
/** Override the toString method */ public String toString() {
// Implement it to return the three sides
return \ \ } }
《Java编程基础》试卷 第 11 页 共 11 页