Question

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

Answer 1

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