Answer:
x=0.392 radians
Step-by-step explanation:
Since DE is parallel to AB, then ∠DEA=∠EAB=2x (Alternate angles). (1)
Also, ∠FEB+∠AEB=180°(Straight line property)
⇒4x+∠AEB=180°
⇒∠AEB=180°-4x (2)
Also, ∠EBA+∠EBC=180°
⇒∠EBA=180°-6x (3)
Now, using equations (1), (2) and (3) and the angle sum property in ΔABE, we get
∠EAB+∠AEB+∠EBA=180°
2x+180°-4x+180°-6x=180°
⇒360°-8x=180°
⇒180°=8x
⇒x=22.5°
⇒x=0.392 radians
which is the required value of x.