In a rhombus, opposite angles are equal, and the diagonals bisect the angles. Since \( \angle A = 114° \), then \( \angle C \) (the angle opposite to \( \angle A \)) is also \( 114° \).
The angles \( \angle B \) and \( \angle D \) are the remaining angles in the rhombus, and they are also equal to each other (since they are opposite angles).
To find \( \angle B \), we can use the property that the sum of all angles in any quadrilateral is \( 360° \). Thus, we find:
\[ \angle A + \angle B + \angle C + \angle D = 360° \]
Substituting the known angles:
\[ 114° + \angle B + 114° + \angle B = 360° \] \[ 228° + 2\angle B = 360° \] \[ 2\angle B = 360° - 228° \] \[ 2\angle B = 132° \] \[ \angle B = \frac{132°}{2} = 66° \]
Thus, the measure of angle \( \angle B \) is \( 66° \).
The correct response is: 66°