If the goal is length x and height y, with a woodwork width w, and we assume the woodwork is flat, can only be hit from the front, and has an even width all the way round the goal, the area of the woodwork would be:
2(*y*w*) + (*xw) + 2(w²)
The w² bit is because of the top corners.
The first two factors are proportional to any changes in width and height, but the corners remain constant (if you don't change w)
Depends what you are comparing to.
If the goal is length x and height y, with a woodwork width w, and we assume the woodwork is flat, can only be hit from the front, and has an even width all the way round the goal, the area of the woodwork would be:
2(*y*w*) + (*xw) + 2(w²)
The w² bit is because of the top corners.
The first two factors are proportional to any changes in width and height, but the corners remain constant (if you don't change w)