Please help I don't know what to work off of here I'm really confused

What is the value of the expression below? (81^2)^1/8

Which statement about the relative areas of δabc and δxyz is true? the area of δabc > the area of δxyz the area of δabc < the area of δxyz the area of δabc = the area of δxyz more information is needed to compare.

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