均线公式代码圆、三角形、正方形、正五边形的周长和面积

2020年10月12日发(作者：张峻宁)
public interface J_Shape
{
public abstract double Area();计算并返回N边形的面积
public abstract double Perimeter();计算并返回N边形的面积
}

public class J_Point
{












}

public class J_Triangle implements J_Shape
{




















public J_Point PA,PB,PC;
public J_Triangle(J_Point _PA,J_Point _PB,J_Point _PC)
{








}
public double Sin(J_Point PA,J_Point PB,J_Point PC)
{






double sin,cos;
double a,b,c;
a=((PA.x -PC.x)*(PB.x-PC.x)+(PB.y-PC.y)*(PB.y-PC.y));
b =((PA.x-PC.x)*(PA.x-PC.x)+(PA.y-PC.y)*(PA.y-PC.y)) ;
c=((PA.x-PB.x)*(PA.x-PB.x)+(PA.y-PB.y)*(PA.y -PB.y));
cos=(a*a+b*b-c*c)(2*a*b);
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public double x,y;
J_Point(double _x,double _y)
{


}
public double distance(J_Point _P)求两点之间的距离
{



}
double s;
s=((x-_P.x,2)+(y-_P.y,2));
return s;
x=_x;
y=_y;
if((_PA.x==_PB.x&_PA.x==_P C.x)||(_PA.y==_PB.y&_PA.y==_PC.y))判断三角形的三个







n(该三个点不能组成三角形);
else
{



}
PA=_PA;
PB=_PB;
PC=_PC;
点不在一条直线上
sin=(1-cos*cos);
return sin;
}
public double Perimeter()求三角形周长
{
return ce(PB)+ce(PC)+ce(PC);
}
public double Area()求三角形面积
{
return (0.5*ce(PC)*ce(PC)*Sin(PA,PB,PC));
}
}

public class J_Square implements J_Shape
{
public J_Point P1,P2;P1,P2分别为正方形的两个对角点
public J_Square(J_Point _P1,J_Point _P2)
{
P1=_P1;
P2=_P2;
}
public double Perimeter()求正方形周长
{
return 4*ce(P2)(2);
}
public double Area()求正方形面积
{
return ce(P2)*ce(P2)2;
}
}

public class J_Circle implements J_Shape
{
public double x,y;圆心坐标
public double R;
public J_Circle(double r)
{
x=0;
y=0;圆心位于原点
R=r;
}
public double Area()
{
return (*R*R);
}

2
public double Perimeter()
{
return(*R*2);
}
}

public class J_Pentagon implements J_Shape
{
public J_Point Pa,Pb;
public double r;
public J_Pentagon(J_Point _Pa,J_Point _Pb)
{
Pa=_Pa;
Pb=_Pb;
}
public double J_Lenth()正五边形的边长公式
{
double L;
double cos;
cos=(*54180);
r=ce(Pb);
L=2*r*cos;
return L;
}
public double J_Area()正五边形中一个三角形的面积公式
{
double S;
double sin;
sin=(*72180);
r=ce(Pb);
S=0.5*r*r*sin;
return S;
}
public double Perimeter()求正五边形的周长
{
return 5*J_Lenth();
}
public double Area()求正五边形的面积
{
return J_Area()*5;
}
}

public class J_Answer
{

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public static void main(String args[])
{
J_Point PA = new J_Point(5, 6);
J_Point PB = new J_Point(3, 1);
J_Point PC = new J_Point(9, 5);
J_Triangle T = new J_Triangle(PA, PB, PC);
n(三角形周长是：+ ter());
n(三角形面积是：+ ());
J_Point P1 = new J_Point(0, 0);
J_Point P2 = new J_Point(4, 4);
J_Square S = new J_Square(P1, P2);
n(正方形周长是： + ter());
n(正方形面积是： + ());
J_Shape a=new J_Circle(5);
n(半径为5的圆的面积是+());
n(半径为5的圆的周长是+ter());
J_Point Pa = new J_Point(0, 0);中心点
J_Point Pb = new J_Point(5, 5);其中一个点
J_Pentagon F = new J_Pentagon(Pa,Pb);
n(正五边形周长是 + ter());
n(正五边形面积是 + ());
}
}

运行结果：
三角形周长是：16.714
三角形面积是：12.5417
正方形周长是：16.0
正方形面积是：16.004
半径为5的圆的面积是78.53981633974483
半径为5的圆的周长是31.493
正五边形周长是41.562693777745345
正五边形面积是118.882


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