Problem above, from what I understand you are to find the vertical distance to an edge that is 6 feet from a vertex.

I'm trying to triangulate from the focus distances to the point to create an equation I can equate.

Using distance from the focus(c=

Setting the center at the origin, the distance from 2 foci =

Therefore the point 6 feet from the vertex, which is 19 ft from the origin, and is 39.71ft from the last focus, is equated by:

This is where my approach halts, is my approach wrong? Or is there something I am just not seeing?

Edit answer is ~9.1