Write the equation of the line passes through the point (10, 2) and is perpendicular to the line: y=-5x+7 Please show work

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

Can someone me with #s 8, 9, and 11. with just one of the three also works. prove using only trig identities.

What is the area of the shaded sector?