Advanced physics

Please calculate both dark and bright fringe.And give the answer with the correct significant figure.*** (significant figure)***

15. A laser emitting at 632.8 nm illuminates a double slit. A screen is positioned 2.00 m from the slits. Interference fringes are observed with separation of 1.0 cm. [6 marks] a) Determine the separation of the slits. [3 marks] b) Determine the angle of the first-order fringes. [3 marks]