QA-P19 has several properties. See properties below.
QA-P19 is the intersection point of the tangents at the vertices of the Reference Quadrangle to the QA-DT-P19 Cubic (QA-Cu4).
p (q + r) (q2 + r2) (2 p + q + r)
-p2 + q2 + r2
- QA-P19 lies on these QA-lines:
- QA-P19 is the Reflection of QA-P5 in QA-P21.
- QA-P19 is the Reflection of QA-P16 in QA-P31.
- QA-P19 is the Involutary Conjugate (see QA-Tf2) of QA-P18. As a consequence the line QA-P18.QA-P19 is the common tangent of the circumscribed conics P1.P2.P3.P4.QA-P18 and P1.P2.P3.P4.QA-P19.
- QA-P19 is the Isotomic Conjugate of QA-P20 wrt the QA-Diagonal Triangle.
- QA-P19 is the Anticomplement of QA-P16 wrt the QA-Diagonal Triangle.
- QA-P19 lies on the Conic QA-Co5.
- QA-P19 lies on the Cubic QA-Cu4.