Question

The adjacent angles of a parallelogram are _____.

• A. supplementary
• B. equal
• C. none of the above
• D. complementary

Answer 1

The correct option is A supplementary

ABCD is a parallelogram.
In a parallelogram, the opposite sides are parallel.
Hence, AB || CD and AD is the transversal then,
Then, $\angle$ BAD + $\angle$ ADC = 180° ( Co-interior angles are supplementary).

If AD || BC and DC is the transversal then,
Then, $\angle$ ADC + $\angle$ DCB = 180° ( Co-interior angles are supplementary).

So, in a parallelogram adjacent angles are supplementary.