10. At a building. two corridors 4m wide and 3m wide meet at right angles (see below). What is the maximum possible length of a table that can be carried around the corner? 4 m 11. A coffee filter has a conical shape (see below). It is made from a circle sector with the central angle a such that the volume of coffee held in the filter is maximized. Determine the central angle a in exact form. (Hint: the volume of a cone is V=-mr h, and the central angle is defined by a = =) P