A metal ring is dipped into a soap solution $($nf$=1\mathrm{.}34)$ and held in vertical plane so that a wedge$-$ shaped film forms under the influence of gravity. At near$-$normal illumination with green light $($$\mathrm{\lambda }=514\mathrm{.}53$ nm$)$ from an Argon laser, one can see $12$ fringes per cm$.$ Determine the wedge angle of the soap film.