三角形正方形 圆和正五边形的周长和面积计算 java实现.doc

JAVA实现三角形正方形圆正五边形的周长和面积的计算新建一个包lab_1包里面包括点 三角形 正方形 圆 正五边形还有主函数类六个类；代码如下：package lab_1;/新建一个点类public class Point double x; double y; public Point(double x,double y) this.x=x; this.y=y; public double Getx() return x; public double Gety() return y; package lab_1;/三角形类public class Triangle Point A,B,C;/定义三角形三个顶点public double L,p1,S;/L为周长S为面积public Triangle(Point A,Point B,Point C)/构造函数this.A=A;this.B=B;this.C=C;public double Perimeter()/利用海伦公式计算周长double AB=Math.sqrt(A.Getx()-B.Getx()*(A.Getx()-B.Getx()+(A.Gety()-B.Gety()*(A.Gety()-B.Gety();double BC=Math.sqrt(B.Getx()-C.Getx()*(B.Getx()-C.Getx()+(B.Gety()-C.Gety()*(B.Gety()-C.Gety();double AC=Math.sqrt(A.Getx()-C.Getx()*(A.Getx()-C.Getx()+(A.Gety()-C.Gety()*(A.Gety()-C.Gety(); return L=AB+BC+AC; public double area() /利用海伦公式计算面积 double AB=Math.sqrt(A.Getx()-B.Getx()*(A.Getx()-B.Getx()+(A.Gety()-B.Gety()*(A.Gety()-B.Gety();double BC=Math.sqrt(B.Getx()-C.Getx()*(B.Getx()-C.Getx()+(B.Gety()-C.Gety()*(B.Gety()-C.Gety();double AC=Math.sqrt(A.Getx()-C.Getx()*(A.Getx()-C.Getx()+(A.Gety()-C.Gety()*(A.Gety()-C.Gety();p1=(AB+BC+AC)/2;return S=Math.sqrt(p1*(p1-AB)*(p1-BC)*(p1-AC);/返回面积 package lab_1;/正方形类public class Square Point D,E;/定义正方形的对角定点 public Square(Point D,Point E) /构造函数 this.D=D; this.E=E; public double Perimeter() double a,L;/a正方形边长,L正方形周长 double DE=Math.sqrt(D.Getx()-E.Getx()*(D.Getx()-E.Getx()+(D.Gety()-E.Gety()*(D.Gety()-E.Gety(); a=Math.sqrt(DE*DE/2); return L=4*a; public double area() double S;/定义面积 double DE=Math.sqrt(D.Getx()-E.Getx()*(D.Getx()-E.Getx()+(D.Gety()-E.Gety()*(D.Gety()-E.Gety(); double b=Math.sqrt(DE*DE/2); return S=b*b;/返回面积 package lab_1;/圆类public class Circle Point F;/圆心坐标 double r;/r为圆的半径 public Circle(Point F,double r) /构造函数 this.F=F; this.r=r; public double Perimeter() double L=Math.PI*2*r; return L; public double area() double S=Math.PI*r*r; return S; package lab_1;/正五边形类public class Pentagon Point G;/正五边形中心点 Point H;/正五边形任意一个顶点 public Pentagon( Point G,Point H) this.G=G; this.H=H; public double Perimeter() double GH=Math.sqrt(G.Getx()-H.Getx()*(G.Getx()-H.Getx()+(G.Gety()-H.Gety()*(G.Gety()-H.Gety(); double f=GH*(Math.sin(36*Math.PI/180);/f为边的一半 double L=10*f;/计算周长 return L; public double area() double GH=Math.sqrt(G.Getx()-H.Getx()*(G.Getx()-H.Getx()+(G.Gety()-H.Gety()*(G.Gety()-H.Gety(); double g=GH*(Math.cos(36*Math.PI/180);/计算三角形的高 double f=GH*(Math.sin(36*Math.PI/180);/f为边的一半 double S=5*g*f;/计算面积 return S; package lab_1;/主函数调用类public class main public static void main(String args) /三角形的三个顶点坐标Point A=new Point(1,0);Point B=new Point(4,2);Point C=new Point(2,4);Triangle x1=new Triangle(A,B,C);System.out.println(三角形的面积是： +x1.area();System.out.println(三角形的周长是： +x1.Perimeter();/正方形的对角点坐标 Point D=new Point(1,1); Point E=new Point(4,4); Square x2=new Square(D,E); System.out.println(正方形的面积是： +x2.area();System.out.println(正方形的周长是： +x2.Perimeter(); /圆的圆心和半径Point F=new Point(4,5);double r=4.00;Circle x3=new Circle(F,r);System.out.println(圆的面积是： +x3.area();System.out.println(圆的周长是： +x3.Perimeter();/新建正五边形的中心点和一个圆点Point G=new Point(3,3);Point H=new Point(5,5);Pentagon x4=new Pentagon(G,H);System.out.println(正五边形的面积是： +x4.area();System.out.println(正五边形的周长是： +x4.Perimeter();运行结果：三角形的面积是： 5.000000000000003三角形的周长是： 10.557