Which equation has a constant of proportionality equal to three

Mr. bernard needs to order more boxes for his 16 inch diameter “super pizza.” use 3.14 to approximate π.

The angle of a triangle are given as 6x,(x-3), and (3x+7). find x then find the measures of the angles

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