For example, a triangle is a plane figure composed of three line segments that are not on the same line. Through experiments and research, we know that the sum of the inner angles of a triangle is 180 degrees, and the sum of the outer angles is 360 degrees. The ground can be covered by six regular triangles.
Look at the regular quadrangle, which can be divided into two triangles. The sum of internal angles is 360 degrees, the degree of an internal angle is 90 degrees, and the sum of external angles is 360 degrees. The ground can be covered by four regular quadrangles.
What about regular pentagons? It can be divided into three triangles, the sum of internal angles is 540 degrees, the degree of one internal angle is 108 degrees, and the sum of external angles is 360 degrees. It cannot cover the ground.
Hexagon can be divided into four triangles, the sum of internal angles is 720 degrees, the degree of one internal angle is 120 degrees, and the sum of external angles is 360 degrees. The ground can cover three regular quadrangles.
A heptagon can be divided into five triangles with an inner angle of 900 degrees, an inner angle of 900/7 degrees and an outer angle of 360 degrees. It cannot cover the ground.
From this, we get that. N polygons can be divided into (n-2) triangles, the sum of internal angles is (n-2)* 180 degrees, the degree of an internal angle is (n-2)* 180÷2 degrees, and the sum of external angles is 360 degrees. If (n)
We can not only cover the ground with a regular polygon, but also cover the ground with two or three kinds of figures.
For example: regular triangle and square, regular triangle and hexagon, square and octagon, regular pentagon and octagon, regular triangle and square and hexagon. ...
In real life, we have seen all kinds of patterns composed of regular polygons. In fact, many patterns are often composed of irregular basic graphics.