In an isosceles triangle that has exactly two equal sides, the equal sides are called legs and the third side is called the base. The angle included by the legs is called the vertex angle and the angles that have the base as one of their sides are called the base angles.
The focus is left of the vertex, so the parabola opens to the left. The vertex is halfway between the focus and directrix, so the directrix is the vertical line x = 2
