java实现三角形面积和周长计算的简单程序

/**
 * 这是一个计算三角形的面积和周长程序<br>
 * findArea方法计算三角形的面积<br>
 * findPerimeter方法计算三角形的周长<br>
 * main函数中的代码是测试之用<br>
 * <br>
 * 这个程序来自于<<java语言程序设计>>第八章编程练习的练习题，并参考了该书第四章编程练习<br>
 * 4.13 中利用三条边计算三角形面积和公式s=(a+b+c)/2, 面积是s(s-a)(s-b)(s-c）的平方根。<br>
 */
public class T {
  private double side1, side2, side3;

  // Construct a triangle with the specified sides
  public T(double side1, double side2, double side3) {
    this.side1 = side1;
    this.side2 = side2;
    this.side3 = side3;
  }

  // Find the area of this triangle
  public double findArea() {
    double area, s;
    s = (side1 + side2 + side3) / 2;
    area = Math.sqrt(s * (s - side1) * (s - side2) * (s - side3));
    return area;
  }

  // Find the perimeter of this triangle
  public double findPerimeter() {
    return side1 + side2 + side3;
  }

  // Override the toString method
  public String toString() {
    // Implement it to return the three sides;
    return "first side is:" + side1 + "; second side is:" + side2 + "; thrid side is:" + side3;
  }

  public static void main(String args[]) {
    T tests = new T(1, 1.5, 1);
    System.out.println(tests.toString());
    System.out.println("The area is: " + tests.findArea());
    System.out.println("The perimeter is:" + tests.findPerimeter());
  }
}