Length is a measure of one-dimensional space and the distance from point to point. Usually, when measuring the side length of a line segment in two-dimensional space, the one with a large length value is called long, which is neither greater than its value nor wider than the side length. So width is actually a measure of length, so the height of "vertical length" is measured in three-dimensional space.

If a vertical line is drawn from the vertex of a triangle to its opposite side (or the straight line where the opposite side is located), then the line segment between the vertex and the vertical foot is called the height line of the triangle, which is called height for short.

The size of the plane figure occupied by objects is called their area. Area is the size of a plane figure, square meters, square decimeters and square centimeters, which is a recognized unit of area and can be expressed as (m? ，dm？ ，cm？ )。

Volume is a technical term in geometry, which is the amount of space occupied by an object. The international unit of volume system is cubic meters. The volume of a solid object is a numerical value that describes the space occupied by the object in three-dimensional space. One-dimensional space objects (such as straight lines) and two-dimensional space objects (such as squares) have zero volumes in three-dimensional space.

Extended data:

Correlation conversion formula:

I. Conversion of quantity

1, cuboid:

(cuboid volume = length × width × height)

2. Cube:

(Cubic volume = side length × side length × side length)

3, cylinder (circle):

Volume of cylinder (perfect circle) = π× (bottom radius× bottom radius )× height.

The volume of the above three-dimensional graphics can be summarized as:

(bottom area × height)

4. Cone (perfect circle):

Cone (perfect circle) volume = π× bottom radius× bottom radius× height /3

5. Pyramid:

Pyramid product = bottom area × height /3

Second, the area conversion

1, rectangle:

{Rectangular area = length× width}

2. Square:

{Square area = side length × side length}

3, parallelogram:

{parallelogram area = base × height}

4. Triangle:

{Triangle area = base × height ÷2}

5, trapezoidal:

{Trapezoidal area = (upper bottom+lower bottom) × height ÷2}

Baidu Encyclopedia-Volume

Baidu encyclopedia-special area