English: Equivalence of a quadratic Bezier curve and a segment of a parabola. Tangents to the parabola at the end-points of the curve (A and B) intersect at its control point (C). If D is the mid-point of AB, the tangent to the curve which is perpendicular to CD (dashed cyan line) defines its vertex (V). Its axis of symmetry (dash-dot cyan) passes through V and is perpendicular to the tangent. E is either point on the curve with a tangent at 45 degrees to CD (dashed green). If G is the intersection of this tangent and the axis, the line passing through G and perpendicular to CD is the directrix (solid green). The focus (F) is at the intersection of the axis and a line passing through E and perpendicular to CD (dotted yellow). The latus rectum is the line segment within the curve (solid yellow).