Inequalities in bicentric quadrilateral

Ediție în limba engleză Marius Drăgan, born on 23 May 1968 in Bucharest, is principal and teacher of mathematics at „Mircea cel Batrân” high school in Bucharest. He published an impressive number of original problems in all the mathematical magazines in România and some of them even abroad. At the same time, he has participated, as an author and member of jury in various national and international mathematical contests.   He has also published an important number of methodical and scientific articles. In this respect the author has also published various issues collaborating with many famous publishing houses and reviews in România and abroad editing scientific and methodology books.