Question

The diagonals of a parallelogram ABCD intersect at O. If $\angle BOC={90}^o$ and $\angle BDC={50}^o$, then $\angle AOB$ is

• A. ${10}^o$
• B. ${40}^o$
• C. ${50}^o$
• D. ${90}^o$

Answer 1

The correct option is D ${90}^o$

It is given that angle BOC = 90.

It means the diagonals cut each other at a right angle.

Angle AOB= 180- Angle BOC =90

So, angle AOB = angle BOC = 90.

So the correct answer is option D.

The data that $\angle BDC={50}^{\circ }$ is not required.