Solution:18×18 ÷ 36 = 324 ÷ 36 = 9 (meters) A: The width of the rectangular lawn is 9 meters.

When the space occupied by an object is a two-dimensional space, the size of the space occupied is called the area of the object, which can be plane or curved. Square meters, square decimeters and square centimeters are recognized units of area and can be expressed as (m? ，dm？ ，cm？ )。

Area is a quantity indicating the degree of a two-dimensional figure or shape or plane layer in a plane. A surface region is a simulation on a two-dimensional surface of a three-dimensional object. Area can be understood as the amount of material with a given thickness, which is necessary to form a shape model.

Area is a quantity indicating the degree of a two-dimensional figure or shape or plane layer in a plane. A surface region is a simulation on a two-dimensional surface of a three-dimensional object. Area can be understood as the amount of material with a given thickness, which is necessary to form a shape model, or the amount of paint required to cover a surface with a single coating. It is a two-dimensional simulation of curve length (one-dimensional concept) or solid volume (three-dimensional concept).

The area of a shape can be measured by comparing a fixed size shape with a square. In the International System of Units (SI), the standard unit area is square meters. A square area with an area of one meter and an area of three square meters will have the same shape as three such squares. In mathematics, the unit square is defined as 1, and the area of any other shape or surface is a dimensionless real number.

The benefits of learning mathematics

People who are good at math are relatively smart and savvy, and they can show their advantages in dealing with people. The faster you think, the more ways and ideas you have. Cambridge, majoring in financial mathematics at Carnegie Mellon University in the United States, said that studying mathematics has brought her mental exercise and made me pay more attention to the rigor of thinking in my life.

For example, before solving a problem, I like to divide it into several sections, and each section is divided into several steps, so that I can dig slowly like a branch instead of thinking in confusion in front of a pile of data. Mathematics is the foundation of other disciplines, and it is easier for people who learn mathematics well to get into other disciplines. Learning software, computer, finance and other engineering majors is even more handy.

Can manage money better than others. The application of mathematics in life is everywhere. Nowadays, the society is already an information society, and mathematical knowledge is used in financial management and computers. Warren Buffett is very powerful, but Buffett's power is also based on mathematics. Buffett's decision-making process is actually the method of using subjective probability.