How thick are the legs 2X3?

If the leg of the table is a cuboid, then its thickness is a cross-sectional area, which can be referred to as follows:

If the units represented by 2×3 of a table leg are all centimeters, then its cross-sectional area is 2×3=6 square centimeters thick.

If the leg of the table is a cylinder, its thickness is determined by the area of the circle, and the thickness can be calculated by the square of the area formula πr of the circle.

In fact, in ordinary life, we usually describe a thing by measuring its thickness. For example, when we see a big tree, its thickness is obviously the cross-sectional area, but few people calculate it in life, just to compare and describe how thick it is.