MathNet 2016-part-01 — 184 problems (EN–VI) Question 98

Any diagonal connecting two opposite vertices of a convex hexagon divides this hexagon into two quadrilaterals. Six quadrilaterals can be obtained in this way.
Find the greatest number of these quadrilaterals that can occur circumscribed quadrilaterals.
(S. Mazanik, I. Voronovich)