Answer:

This part of the extended information mainly examines the knowledge points in this field:

Area represents the number of two-dimensional graphics or shapes in a plane or the number of layers 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.

Common units of area are square centimeter, square decimeter and square meter.

(1) A square with a side length of 1 cm and an area of1cm 2.

(2) A square with a side length of 1 decimeter and an area of 1 square decimeter.

(3) A square with a side length of 1m and an area of 1m2.

Generally, hectares and square kilometers are used to measure large areas.

(1) Square with side length 1 00m and area1hectare.

(2) A square with a side length of 1km and an area of 1km.