It’s geometry can anyone help me? Find the length of BH

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

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

What is the factor form of x^2-9x+14