Plz me with this. write 0.12 in words

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

Geometry - finding area of regular polygons and sectors (check my math, i can’t find the error)

Gables properties corp. is leasing office building with an area of 49b^2+70b+25. what is the shape of the building? a) rectangle b) square