Let S△OBE=x and s △ OCF = Y.

Calculate the heights of △BEF and △CEF (based on EF) respectively.

∫AB∑CD, and AB= 1/2*CD.

The ratio of the two heights is 1: 2.

S△BEF:S△CEF= 1:2

5+y=2(5+x)

Get y=5+2x.

There is OE: oc = s △ OEF: s △ OCF = 5: (5+2x) = 5/(5+2x).

OF:OD=S△OEF:S△OEB=5:x=5/x

s△OEF = 1/2 * OE * OF * sin∠EOF = 5

s△OBC = 1/2 * OB * OC * sin∠BOC = 17

Get 5/(5+2x) * 5/x=5/ 17.

Simplify by 2 times? +5x=85

The solution is x≈5.39 (negative)

Connect AC to get S△ABC = S△OBC+S△OBE+S△ Abe -S△AEB.

= 17+x+(5+x)-(5+y)S△AEB = S△FEB S△AEC = S△FEC

= 12

S△ADC = 2 * S△ABC = 24 AB∨CD，AB= 1/2*CD。

S△CDF=S△ACD-S△AEC-S△FEC

=24-2(5+y)

=4-4x ≈ - 17.66？