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.