Ten trees are planted in nine rows, four in each row, how to arrange them? 5

Impossible, 5 trees per row is ok.

10 trees should be arranged in 5 rows, 4 trees in each row, how to arrange them?

Pose in the shape of a "five-pointed star". (Someone asked a similar question just now, that problem is to place chess pieces, see draw five straight lines, let the five straight lines intersect in pairs, there are 10 intersection points.) (e.g. pentagram) on these 10 intersections, put 10 trees, and you're good to go.

Proof that five straight lines intersect to form 10 intersections:

Two straight lines intersect to form an intersection point.

Add another line so that this line intersects with the two lines above it, forming two new intersections.

By analogy, when the nth straight line is added, the nth straight line intersects with the n-1 straight line in front of it, forming a new n-1 intersection point.

So, five straight lines can be formed: 1+2+3+4 10 (this is also the maximum number of intersection points that can be formed).

Resources.

It's too simple, kindergarten game, one stroke to draw a five-pointed star arrangement.

The garbage problem, this is not a brain teaser, this is a math problem, and you can only understand it when you learn it well in high school

Cocoa. Cocoa.

Yes, you can. To take it to the end.

A "to" character is a tree.

Look at 3 rows horizontally. Look at 3 lines vertically.

Look at 3 lines obliquely.

Arrange in a regular triangle with 4 trees on each side.

It's a little hard, but.

oo o o oo oo

o o is also not right.

Impossible! Let's take a look.

Solution: Nine trees, plant ten rows, 3 trees in each row, and the planting method is as follows:

Test point: The law of the combination of number and shape.

Special Topic: Exploring the Laws of Numbers.

Analysis: Nine trees, plant ten rows, 3 trees in each row, and draw two equilateral triangles side by side on the left and right The position is: the vertex of the triangle on the right is placed on the midpoint of the bottom edge of the triangle on the left, and the vertex of the triangle on the left is at the key point of the bottom edge of the triangle on the right.

In this way, a symmetrical figure is formed, and a point is drawn in the center of the two equilateral triangles, with a total of 6 vertices, plus 2 waist intersection points, plus a point in the center, a total of 9 points, and 9 trees are planted The sides of the equilateral triangle have a total of 6 lines, and there are 4 more lines through the three points and one line of the center line, a total of 10 lines.

Three horizontal rows, one vertical row, two diagonal cross rows, two isosceles triangles in the middle four rows.

As shown below:

The dots represent the tree.

Numbers indicate rows.

9 trees, planted in 10 rows, 3 in each row.

Use 9 trees to plant 10 rows, and the specific planting steps are as follows:

1. In a plane, change to a large rectangle, and draw a cutting line in the rectangle to turn it into two small rectangles.

2. Connect the diagonal sides of two small rectangles to each other.

3. Plant a tree at the location where the star is marked, and you can get ten rows. (3 horizontal + 6 oblique + 1 vertical).

Refer to the diagram below.

Maybe there is no single answer, there is a better or other way to share.

Nine burning cherry trees, planting ten rows, 3 trees per disadvantage, planting the slag method is as follows:

Plant three trees in each row in the following way:

One row up and down, a total of 2 rows, 2 rows in the middle cross, 2 rows in the diagonal diagonal, 2 rows in the upper midpoint and below, and 2 rows in the lower midpoint and above.

There are 10 rows in total.