I need help with this question please

(20 pts ) Light of wavelength 650 nm from a distant source is incident on a slit 2.40 um wide, and the resulting diffraction pattern is observed on a screen 4.0 m away. Do not assume the angles are small. (a) (6 pts) What is the distance between the two dark fringes on either side of the central bright fringe? (b) (4 pts) Does increasing the size of the slit increase or decrease the size of the central bright fringe? Explain your answer. (c) (10 pts) Draw a graph of intensity versus angle from 90 to +90. Your graph should have the correct number of maxima/minima, so you must calculate something to make this plot