Fie ABCD trapez dreptunghic, AB || CD, AB > CD, AD _|_AB , ABC = 60°
Sa se afle aria trapezulu.
---------------------------------------------------------------------------------------------
Fie E∈ AB, a.i. CE _|_ AB
AB - CD = EB
Din ipoteza in triunghiul dreptunghic in E, ΔCEB , CE / EB = tg60°
CE = EB*tg60°
Aria = CD*EB*tg60° + (1/2)*EB²*tg60°
