Answer:
70°
Explanation:
As, the sum of the angles in a straight line is 180°.
<E F C + < E F B = 180
70 + < E F B = 180
< E F B = 180 - 70
< E F B = 110°
Also, we know that the sum of the interior angles in a quadrilateral is 360°
So,
< E A B + < A E F + < E F B + < F B A = 360
90 + 90 + 110 + x = 360
290 + x = 360
x = 360 - 290
x = 70°
Hope this helps you :-)
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