Copper coin area = circular area-square area =πr? -a？ . Where r=28÷2= 14 (mm), a=6 mm, and π is 3. 14. Copper coin area =3. 14× 14? -6? =6 15.44-36=579.44 (mm2)。 A: The area of this copper coin is 579.44 square millimeters.
Mbth (area) is a quantity used to represent the area occupied by a curved surface or a plane figure, which can be regarded as a two-dimensional analogy of length (one-dimensional measurement) and volume (three-dimensional measurement). For three-dimensional graphics, the area of the graphics boundary is called the surface area.
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.
There are several well-known formulas for simple shapes, such as triangle, rectangle and circle. Using these formulas, you can find the area of any polygon by dividing it into triangles. For shapes with curved boundaries, calculus is usually needed to calculate the area. In fact, the problem of determining the digital area of aircraft is the main driving force for the historical development of calculus.
For solid shapes such as spheres, cones or cylinders, the area of the boundary surface is called the surface area. The surface area formula of simple shapes was calculated by the ancient Greeks, but calculating the surface area of more complex shapes usually requires multivariable calculus.
Region plays an important role in modern mathematics. Area is not only important in geometry and calculus, but also related to the definition of decisive factors in linear algebra, which is the basic feature of surfaces in differential geometry. In the analysis, Lebesgue measurement is used to define the area of a subset of planes, although not every subset is measurable. Generally speaking, the field of advanced mathematics is regarded as a special case of two-dimensional regional volume.
This region can be defined by using axioms as a function of some sets of planar graphs and real numbers. It can be proved that such functions exist.