Triangle AEC, AE = be, D and C are a point on AE and EB respectively and de = CE. Is quadrilateral ABCD isosceles trapezoid? Why?

Triangle AEC, AE = be, D and C are a point on AE and EB respectively and de = CE. Is quadrilateral ABCD isosceles trapezoid? Why?

AE = be, triangle is AEC, where does B come from? Please clarify the question first
I don't understand