What did the double-slit experiment (also called Young's Experiment) demonstrate?

Suppose a light with a wavelength of passes a pair of slits with a separation of . Determine the angle which corresponds to the first bright fringe.

Red light (wavelength ) is sent through a double slit. The slits are apart. The light then hits a screen which is behind the double slit. How far is the first bright fringe from the second bright fringe?

Suppose that a diffraction experiment is performed in order to determine the wavelength of light. As light of an unknown wavelength is passed through a slit, a diffraction pattern is observed. If the first dark fringe is found to occur at an angle of away from the slit, what is the wavelength of this light?

What was a result of Young's double slit experiment?

Suppose light pass through a slit with a width . The diffraction pattern angle is for the first dark fringe. What is the light's wavelength?