Which machine are you wanting the dimensions for?
imac, ibook, powerbook?
Let us know
The ibook g3 12.1 dimensions are Width 11.2 inches Depth 9.1 inches Thickness 1.35 inches and a weight of 4.9 Pounds.
The full machines specs can be found here http://support.apple.com/specs/ibook/iBook_Dual_USB.html
Let us know if you need more info.