Given a triangle abc and a line p not on a vertex.?

Question

Construct a quadrilateral pqrs having abc as diagonal triangle. Is the quadrilateral unique?

hint. Let (a*b)(c*p) = d, (a*c)(b*p) = g, (b*c)(d*g)= h, then (a*h)(b*g) = s, (a*h)(c*d) = r, (b*r)(c*s) = q.

Answer 1

How can we do this without a figure?