Question

In figure AB || CD. Determine $\angle a$

Answer 1

Through O draw a line l parallel to both AB and CD.
Clearly, $\angle a=\angle 1+\angle 2$...(ii)
Now, $\angle 1={55}^{\circ }$ [Alternate $\angle s$]
and $\angle 2={38}^{\circ }$ [Alternate $\angle s$]
$\therefore \angle a={55}^{\circ }+{38}^{\circ }$ [Using (i)]
$\Rightarrow \angle a={93}^{\circ }$
Thus, $\angle a={93}^{\circ }$