Coherent light from a laser diode is emitted through a rectangular area $3\mathrm{.}1$ m $1\mathrm{.}5$ m $($horizontal$-$by$-$vertical$).$ The laser light has a wavelength of $840$ nm$.$ Determine the angle between the first diffraction minima above and below the central maximum. Determine the angle between the first diffraction minima to the left and right of the central maximum.