Question 111
In the given figure, Find out which pair of lines are parallel.
From the given figure,
∠1=180∘−123∘⇒∠1=57∘
Also ∠2=180∘−57∘⇒∠2=123∘
Now, ∠1+∠2=57∘+123∘=180∘If sum of the consecutive angles are 180∘ then the lines are parallel.
∴EF||GH
Now, ∠3=180∘−∠2⇒∠3=180∘−123∘=57∘
Also, ∠4=180∘−55∘=125∘∴∠3+∠4=57∘+125∘=182∘≠180∘
So, GH and KP are not parallel.
Also, ∠3+122∘=57∘+122∘=179∘≠180∘Hence, AB and CD are not parallel.