In order to enclose a larger area, it is arranged in a rectangle along the wall, and the old wall is used for the long side.

That is, 24 meters is four wide sides and three long sides.

4* width +3* length = 24

Precisely

4 * 3+3 * 4 = 24 The area is 3*4*3 = 36.

Therefore, the length is 4, the width is 3 and the area is 36.