Use the result of Problem 4.52 to determine the capacitance

Use the result of Problem 4.52 to determine the capacitance for each of the following configurations:
(a) Conducting plates are on top and bottom faces of rectangular structure in Fig. 4-35(a) (P4.53 (a)),
(b) Conducting plates are on front and back faces of structure in Fig. 4-35(a) (P4.53 (a)),
(c) Conducting plates are on top and bottom faces of the cylindrical structure in Fig. 4-35(b) (P4.53 (b)).