Hello, please answer and explain :

In this part, you use a red laser pointer (with a given wavelength of 636 nm), a series of diffraction slits (single and double), and a black screen.

The screen is at a distance of = 40.0 cm from the slits. You notice that the patterns show constructive (bright spots) and destructive (dark spots) interference regions. You take a picture of the diffraction pattern for each slit (Figure 1).