public void CircleProjectionToPlaneTest()
{
Vector3d v1 = new Vector3d(3, 5, 1);
Circle3d c = new Circle3d(new Point3d(5, 6, 1), 5, v1);
Plane3d s = new Plane3d(5, 2, 3, -3);
Point3d p = c.ParametricForm(0.5).ProjectionTo(s);
Assert.IsTrue(p.BelongsTo(c.ProjectionTo(s)));
p = c.ParametricForm(0.725).ProjectionTo(s);
Assert.IsTrue(p.BelongsTo(c.ProjectionTo(s)));
p = c.ParametricForm(2.7122).ProjectionTo(s);
Assert.IsTrue(p.BelongsTo(c.ProjectionTo(s)));
}