Question

In the figures given, state whether the lines $l$ and $m$ are parallel or not.

Answer 1

(i) ${106}^{\circ }+{67}^{\circ }={173}^{\circ }$

Since sum of co-interior angles is not ${180}^{\circ }$

Therefore given lines $l$ and $m$ are not parallel.

(ii) Alternate interior angle of ${75}^{\circ }$$={180}^{\circ }-{75}^{\circ }={105}^{\circ }$

Since alternate interior angles are not equal

Therefore, given lines $l$ and $m$ are not parallel.

(iii) Corresponding angle of ${57}^{\circ }$$={180}^{\circ }-{123}^{\circ }={57}^{\circ }$

Since, the corresponding angles are equal

Therefore the given lines $l$ and $m$ are parallel