I am puzzled as well with your question, because there doesn't appear to be enough information in it. Specifically, it doesn't say what the shape or the volume is.
Let's say it is a fence post. The "girth" (according to my dictionary) is the circumference and the length is just the length, so we can quickly figure out the radius or diameter or even the volume of the post, but what does "width" and "height" mean? Perhaps it means length and diameter, which we know.
Let's say it is dimensional lumber (like a 2 by 4 which is actually 1 3/4 inches by 3 3/4 inches). The "girth" would be the perimeter around its short dimensions (so the width and depth added together and then doubled would be 11"). The width and depth may be what the question means by width and height, but there are infinite solutions to this. For example, if the lumber is 11/4" on each side, then the girth is 11" (that's one answer) but if the lumber is 1" thick and 4.5" width, the girth is also 11".
Knowing the volume would help a bit, but knowing the shape would help to nail this question down. Just what are we measuring?
Stephen La Rocque.>