Triangle wedge to Arch wedge

[ShadowRunner666]

I need to change a triangle with a curved side into a arch shaped wedge.
The triangle is made up of 4 points along the outside edge connected to the middle point, so what I need to do is created 4 new points close to the ouside edge and have the colored faces connect with it.

Tbat::Tbat(void)
{
	int i = 0;
	double angle = 0.0, rad_angle = 0.0;
	double z = 0.0; 
	double x = 0.0;
	double y = -4.0;
	for(i=0;i<=9;i++)
	{
		//int angle=10*i;

		//Transform degrees into rads
		rad_angle=(pi*angle)/180.0;
		//Calculate the x and z co-ordinates or circle ground
		x=radius/(sqrt(1.0+tan(rad_angle)*tan(rad_angle)));
		z=radius*(sqrt(1.0-(1.0/(1.0+tan(rad_angle)*tan(rad_angle)))));
		angle+=10;

		//Quadrant co-ordinates of ground
		if((i>=2)&&(i<9))   //First Quad
		{
			if(i==9)
			{
				_points[i]=TVector(0.0, 0.0, 1.0);
			}
			_points[i]=TVector(x,y,z);
		}

	_normal = TVector(0.0, 1.0, 0.0);
	}
	///// and the back
	for(i=0;i<=9;i++)
	{
		//int angle=10*i;

		//Transform degrees into rads
		rad_angle=(pi*angle)/180.0;
		//Calculate the x and z co-ordinates or circle ground
		x=(radius-20)/(sqrt(1.0+tan(rad_angle)*tan(rad_angle)));
		z=(radius-20)*(sqrt(1.0-(1.0/(1.0+tan(rad_angle)*tan(rad_angle)))));
		angle+=10;

		//Quadrant co-ordinates of ground
		if((i>=2)&&(i<9))   //Front Quad
		{
			if(i==9)
			{
				_points1[i]=TVector(0.0, 0.0, 1.0);
			}
			_points1[i]=TVector(x,y,z);
		}

	_normal = TVector(0.0, 1.0, 0.0);
	}
	
}

Tbat::~Tbat(void)
{
}


void Tbat::DrawBat()
{
	int i=0.0;
	glPushMatrix();
	glPushAttrib(GL_ENABLE_BIT);
	glCallList(50);
	glEnable(GL_TEXTURE_2D);

	glBegin(GL_POLYGON);
	for(i=0; i<=9; i++)
	{
		glNormal3f(0.0, 0.0, 0.0);
		glVertex3f(_points[i].X(), _points[i].Y(), _points[i].Z());
	}
	glEnd();



	glBegin(GL_POLYGON);
	for(i=0; i<=9; i++)
	{
		glNormal3f(0.0, 0.0, 0.0);
		glVertex3f(_points[i].X(), _points[i].Y()+25, _points[i].Z());
	}
	glEnd();

	for(i=0; i<=9; i++)
	{
	glBegin(GL_POLYGON);
	
		
	//	glNormal3f(0.0, 0.0, 0.0);
	glColor3f(0.0, 0.0, 1.0);
	glVertex3f(_points[i].X(), _points[i].Y(), _points[i].Z());
	glVertex3f(_points[i].X(), _points[i].Y()+25, _points[i].Z());
	glColor3f(1.0, 0.0, 1.0);
	glVertex3f(_points[i+1].X(), _points[i+1].Y()+25, _points[i+1].Z());
	glVertex3f(_points[i+1].X(), _points[i+1].Y(), _points[i+1].Z());
	
	glEnd();
	}
	glDisable(GL_TEXTURE_2D);
	glPopAttrib();
	glPopMatrix();
}

This is the current code I have for making the triangle/bat. I just have no clue how to define the new points that I need to make to connect the faces to