Given the circle O with perpendicular diameters and a chord, find the area of the circle if EF = 8" and DE = 20" (DF = 12"). (integer)
DE is a chord that intersects one of the diameters and shares a point on the circle with another (click on hyperlink below to see a picture).
It is not a 30-60-90 right triangle; it has been tried and does not produce the correct answer.
The correct answer: 377 sq. inches
If you understand how to do this problem or know the proof behind it, please help me with this.