Question

Statement Reason
$\angle 1+\angle 8={180}^o$ .......................

Answer 1

Reason $:$

$\angle 1=\angle 5$ (Corresponding angles as $l||m$)

$\angle 5+\angle 8={180}^{\circ }$ (Supplementary angles made on a line at a point)

Put $\angle 5=\angle 1$

$\angle 1+\angle 8={180}^{\circ }$