What is the area of triangle ODF?

The area of the shaded part of sector OAB is 1,500PI. OA=70 and the sector angle is 2PI/3 . Point E is the first point from B among the points dividing arc AB into four equal parts. When point D divides the line segment CE into 3 to 2, what is the area of triangle ODF? #SAT#ACT#MATH#Geometry#Trigonometry