How to make 5 triangles of the same size with 9 matches

As shown in the picture, you can tear it down to make a match

How many triangles can 6 matches form at most? How many triangles can 9 matches form at most!

In plane, six matches of the same length can form up to two triangles, but in space, four triangles can be formed,
Therefore, this problem should be considered from the space. Therefore, 6 matches can form up to 4 triangles, and 9 matches can form up to 7 triangles
Six matches happen to be a tetrahedron
Nine matches are two regular tetrahedrons
One of their faces is shared
Think about it

How to make 4 triangles with 6 matches

Is a square, and then connect the two diagonals, just four triangles in the middle

Use six matches to form four triangles of the same size. The name of the figure is______ ．

A triangular pyramid is surrounded by four triangles, so six matches are used to form four triangles of the same size. The name of the figure obtained is a triangular pyramid. So the answer is a triangular pyramid

Using six matches to form four triangles of the same size, what is the name of the figure?
The respondent had better explain how to spell out four triangles,

Do you know a tetrahedron? It's just like a triangle with one face ~ it just needs 6 matches ~ I think of it like a pyramid ~ it's spelled out! Ha ha, I'm so smart

Can you make four identical triangles with six matchsticks? If so, what is the pattern?
A equilateral triangle B regular triangle C regular triangular pile D triangular pile

C-regular pyramid
It is also called regular tetrahedron

Use 10 matchsticks to put a triangle, can put - -

According to "the sum of the two sides of any triangle is greater than the third side", there are three kinds of pendulum
①3,3,4；②2,4,4；③1,6,3；

You can make several different triangles with 10 matchsticks

3 kinds
The side lengths of the three triangles are (2,4,4) (3,3,4) (3,4,3)

Three matches in one layer, nine matches in two layers, eighteen matches in three layers, how many matches in twenty layers? Three matches in one layer, nine matches in two layers, ten matches in three layers

Three in one floor = 3 * 1
Nine in the second floor = 3 * (1 + 2)
Three layers and eighteen roots = 3 * (1 + 2 + 3)
.
How many roots on the 20th floor = 3 * (1 + 2 +. + 20)
=3*20*（1+20）/2=630

How to make 5 triangles of the same size with 9 matches