Respuesta :

9514 1404 393

Answer:

  41

Step-by-step explanation:

The product of segment lengths from the point of intersection to the circle is the same for both chords.

  QC·QE = QD·QF

  2x(21) = (x+4)(30)

  14x = 10(x +4) . . . . . divide by 3

  4x = 40 . . . . . . . . . . subtract 10x

  x = 10 . . . . . . . . . . . .divide by 4

  2x +21 = EC = 2(10) +21 . . . . . find EC

  EC = 41