Question

Find x ab parallel cd
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Answer 1

In the given question;

AB//CD

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Angle DAE + Angle AEF = 180,

Because DAE and AEF are co-interior angles.

let Angle AEF be x. then,

$120 + x = 180$

$x = 60$

Angle AEF = 60 degrees.

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Angle DCE + Angle FEC = 180

Because DCE and FEC are co-interior angles.

let Angle FCE be x. then,

$120 + x = 180$

$x = 60$

Angle FCE = 60 degrees

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Angle AEC = Angle AEF + Angle FCE

$= 60 + 60$

$= 120 \: degrees$

Hope it helps.