4.4 Show that the area of the "flat torus" six s' c . of Example 2 , is (27)2. Generalize this computation to show that the area, of the "n- dimensional torus" six ...x s' ...x $' = ,is (2 # )".Example 2 Let Q be the square [0, 2x] x [0, 2x] in the Op-plane , and F : Q - *# the surface patch defined by X1 = cos 0, X3 = COS @, *2 = sin e, XA = sin p. The image of F is the so-called "flat torus" six s' ca x 2 in 4. Note that F is one-to-one on the interior of Q (why?), but not on its boundary [for instance, the four vertices of Q all map to the point (1, 0, 1, 0) EQ4