1 of 4 Using a pencil, pair of compasses and ruler,
construct a triangle with sides 9cm, 4cm
and 6cm. Measure the size of the angle
between the 9cm and 6cm sides to the
nearest degree.

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