In a rhombus, opposite angles are equal, and the adjacent angles are supplementary. Given that \( m∠A = 114° \), we can find \( m∠B \) as follows:
Since \( m∠A + m∠B = 180° \) (adjacent angles are supplementary), we can substitute the known angle into the equation:
\[ 114° + m∠B = 180° \]
Now, solve for \( m∠B \):
\[ m∠B = 180° - 114° \] \[ m∠B = 66° \]
Therefore, the measure of angle \( B \) is \( 66° \).
The correct response is:
66°