Connecting DE
* ADB =∠AEB=90 degrees
∴A, B, D, E four-point * * * cycle
So ∠CED=∠ABC
And l is the tangent of the intersection c of ≥ o.
∴∠ACG=∠ABC
∴∠CED=∠ACG
So de FG
So DF=EG
That's right. I was wrong.