Given that ABCD is a rhombus, what is the value of x?

Answer:
option E (x = 25°)
Step-by-step explanation:
Given ABCD is a rhombus.
Since rhombus is a quadrilateral in which diagonal perpendicular bisect each other.
Therefore, in a triangle formed by two angles x°, (x + 40) and 90°
x + x + 4- + 90 = 180°
2x + 130 = 180°
2x = 180 - 130
2x = 50°
x = 25°
Therefore, option E (x = 25°) is the answer.