Answer:
x= 22.5°
Step-by-step explanation:
∠DEA= ∠BAE (alt. ∠s, DE// AB)
Substitute ∠DEA= 2x:
∠BAE= 2x
∠AEB +∠BEF= 180° (adj. ∠s on a str. line)
Substitute ∠BEF= 4x:
∠AEB +4x= 180°
∠AEB= 180° -4x
∠ABE +∠CBE= 180° (adj. ∠s on a str. line)
Substitute ∠CBE= 6x:
∠ABE +6x= 180°
∠ABE= 180° -6x
∠BAE +∠AEB +∠ABE= 180° (∠ sum of triangle)
2x +180° -4x +180° -6x= 180°
-8x +360°= 180°
8x= 360° -180°
8x= 180°
x= 180° ÷8
x= 22.5°
