A plane polarized light is incident on a polariser with its pass...

A plane polarized light is incident on a polariser with its pass axis making angle $\theta$ with $\mathrm{x}$-axis, as shown in the figure. At four different values of $\theta, \theta=8^{\circ}, 38^{\circ}, 188^{\circ}$ and $218^{\circ}$, the observed intensities are same. What is the angle between the direction of polarization and $\mathrm{x}$-axis