In the given figure ABCD is a rhombus, the value of $x$ is.
Answer & explanation
Correct answer: option 2

Note:
1. In a rhombus diagonals are intersect at right angle.
2. All sides are equal and opposite sides are parallel.
Now, In the rhombus:
\(\angle\)OAB = 40°
\(\angle\)AOB = 90°
\(\angle\)CDB = \(\angle\)DBA = x° (alternate interior angles)
In ΔAOB:
⇒ Sum of all three angles = 180°
⇒ 40° + 90° + x° = 180°
⇒ x = 50°