Help meee please on this one

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

5. (03.02)if g(x) = x2 + 3, find g(4). (2 points)1619811

The triangles are similar. what is the value of x? enter your answer in the box.