PLEASE HELP I HAVE NO IDEA HOW TO DO SLOPES

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters

Someone which statements are true? check all that apply.

The base of a pyramid is a square with 5 lines of 5cm the slant height of each lateral face of the pyramid is 6 cm what is the surface area of the pyramid