so, notice the picture below
based on those points, the parabola is vertical and opening upwards
now, bear in mind that, the vertex is at h,k
and there's a "p" distance from the vertex, to the focus point, and the same "p" distance to the directrix, so, the vertex is really half-way between the focus point and directrix
so... all you need, is to get the "p" distance, and you'd know what h,k are
then plug all three p,h,k in the equation 4p(y - k) = (x - h)²
