Yup it's a single source of light, and i suppose it'll be the same as single slit experiment. It's just trying to understand why, but i got to draw out the lines to understand it. Thanks all!
Hair/wire laser diffraction interference pattern - does it follow single-slit or double-slit?
for single-slit interference, the equation nλ = d (y/D), (d is the width of the single-slit, y is the distance between central BRIGHT fringe to the nth DARK fringe, D is the distance from slit to...