A single-phase full-bridge inverter fed by a 325 V DC produces a symmetric quasi-square waveform across 'ab' as shown. To achieve a modulation index of 0.8, the angle \( \theta \) expressed in degrees should be \(\underline{\hspace{2cm}}\) . (Round off to 2 decimal places.)(Modulation index is defined as the ratio of the peak of the fundamental component of \( v_{ab} \) to the applied DC value.)
