For each of the following descriptions, write a set of polar inequalities. The units for the angles should be given in radians. For each problem, we recommend sketching a picture on a separate piece of paper. The angles you enter should be between $0$ and $2\pi$.
(a) A flat washer with an internal diameter hole of 4 millimeters and an external diameter of 6.8 mm

(b) A pizza has a diameter of 50 centimeters, and has been cut into 12 equal slices. Describe the region taken up by 4 slices of pizza.

(c) A pizza has a diameter of 32 centimeters, and has been cut into 8 equal slices. Furthermore, the crust at the edge of the pizza takes up the last 2 centimeters of each slice. Describe the region covered by toppings of 4 slices of pizza.