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

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

How many matchsticks do you need if there are 2, 3 or 4 triangles in the figure? How many matchsticks do you need if there are n triangles in the figure?

Three matchsticks are used for the first triangle. When a row of triangles is formed, one triangle can be added for every two matchsticks added from the second triangle
P(n)=2*n+1.
P(2)=5,P(3)=7,P(4)=9

There are three matches in the first triangle, nine matches in the second triangle, 18 matches in the third triangle, 30 matches in the fourth triangle and 45 matches in the fifth triangle

1 3,3×1
2 9,3×(1+2)
3 18,3×(1+2+3)
4 30,3×(1+2+3+4)
5 45,3×(1+2+3+4+5)
N (3n2+3n)/2

Use six matchsticks to make four triangles

It's a three-dimensional pyramid. It's like a pyramid. It's a triangle at the bottom and three at the top

Put 4 equilateral triangles of the same size with 6 identical matchsticks. Draw a graphic solution. Thank you

Do you know a big satellite? First use three matches to place an equilateral triangle. Then use more than one other point to place an equilateral triangle. After two opposite triangles overlap, the figure formed is a big satellite. There is a Pentagon in the middle and six equilateral triangles on the outside. If you want four, move up and down any

How many different triangles can be placed on the table with nine identical matchsticks? (all matchsticks are used and can't be broken)

① Three triangles: 1, 4, 4; 2, 3, 4; 3, 3, 3
This problem is mainly solved by the trilateral relation of triangle. Attention should be paid to find out the triangle according to the law to avoid re finding and missing finding
This is a senior high school entrance examination question in Jining in 2004,

Put five triangles on the table with nine identical matchsticks

A rhetorical question: how can six identical matchsticks make four identical triangles?

Use 10 matchsticks of the same length to make a triangle. Can you move three of them to make a pair of congruent triangles

What's the picture like, otherwise it won't move

If you only move three matchsticks, can you make the swallow fly in the opposite direction and the fish swim in the opposite direction?

ddd ↙↖↗↖↗↘
ddddddd ↘↙
First remove three
ddd ↙↖↗↖↗
Then add three
ddddddd ↙↖
ddd ↘↙↖↗↖↗
dddd ↖
ddd ↖↗↘
ddd ↙↘↗
dddd ↙
Take out three first
dddd ↖
ddd ↖↗↘
ddddd ↘
Then add three
ddddd ↗
ddd ↗↖↗
ddd ↖↗↘
ddddd ↘

If you only move three matchsticks, can you make the swallow fly in the direction of the detailed list and the fish swim in the opposite direction

What picture