My first object

I am proud I figured this out

#define PI 3.14159265

void drawCone(int diameter, int height, int numFaces)

{

      //what is the angle

float angle =  360/(float)numFaces;

       //convert to radians

       float radian = (angle * PI)/180;

// get a radius

       float rad  = (float)diameter/2;

       float start = 0;

       //draw CONE

       glBegin(GL_TRIANGLES);

       for (int j  = 0; j < numFaces; j++)

       {

                     glVertex3f(0, 0,(float)height);

                     glVertex3f(cos(start)*rad, sin(start)*rad,0);

start += radian;

                     glVertex3f(cos(start)*rad, sin(start)*rad,0);

       }

       glEnd();

       start = 0;

       //draw BOTTOM

       glBegin(GL_TRIANGLES);

       for ( int k  = 0; k < numFaces; k++){

                     glVertex3f(0,0,0);

                     glVertex3f(cos(start)*rad, sin(start)*rad,0);

                     //reverse to be visible from out side

start -= radian;

                     glVertex3f(cos(start)*rad, sin(start)*rad,0);

       }

       glEnd();
}