Draw a Tangent to an Ellipse at Any Given Point:
To Sketch a Tangent to an Ellipse at Any Given Point
Refer diagram as, given any point as like P on the perimeter of the ellipse ABCD. By using C like a center and a radius equal to OA or say as one half the major diameters, strike arcs across the main axis at F1 and F2. From these points, that is foci of the ellipse, sketch F1P and F2G. The bisector of the angle GPF1 is the desired tangent to the ellipse.