Question

The sum of adjacent angles of a parallelogram is
a) ${180}^{\circ }$
b) ${120}^{\circ }$
c) ${360}^{\circ }$
d) ${90}^{\circ }$

Answer 1

Consider the parallelogram

Since, the opposite sides of a parallelogram are parallel.
So, $AB||CD$ and $BC$ is transversal.
As we know that the interior angles on the same side of the transversal are supplementary.
That is they added to ${180}^{\circ }$
$\therefore \angle B+\angle C={180}^{\circ }$
Hence, the sum of the adjacent angles of a parallelogram is ${180}^{\circ }$
Therefore, the correct option is (a) (${180}^{\circ }$)