Use 12 matches to make a figure with an area of 3 Let the length of the match be 1. This is a primary school information technology examination question. There are two little moles on a piece of grass. Put the two little moles in a passage with a graph. You can only draw a square or a rectangle. You don't need a line segment in the middle of the graph. 12 matches can't be left

Four matches make a square with an area of 1
The area of three squares with 12 matches is three

How to make a square with eight matchsticks into a figure with half its area (the new figure also needs eight matchsticks)
Please explain clearly what the figure is
Use a few at the top and a few at the bottom

The original square is made up of two matches on each side
The new figure is a diamond with two matches on each side
But the four top angles are: 45 degrees, 135 degrees, 45 degrees, 135 degrees

It is known that figure 1 uses 3 matches, 2 uses 9 matches, 3 uses 18 matches, 4 uses 30 matches, 5 uses 45 matches, 6 uses 63 matches, n uses how many matches?

3 (n + 1) n / 2
:1+2+3+4=(1+4)x4/2

Use 9 matches to make a figure with 3 squares and 7 rectangles?

|_ |_ |_ |_|
__ That's one
The top is the same as the bottom

If two matches are used as one side and seven matches as the other side, what is the number of matches that can be used on the third side?

7-2 = 5 (pieces)
7 + 2 = 9 (root)
There are more than 5 matches on the third side and less than 9 matches on the third side

The first figure needs four matchsticks, the second 12, the third 17, and the nth figure needs the number of matchsticks as S. write the formula of s with n

S = -1.5n²+12.5n-7
When n = 1, S1 = - 1.5 * 1 & # 178; + 12.5 * 1-7 = - 1.5 + 12.5-7 = 4
When n = 2, S2 = - 1.5 * 2 & # 178; + 12.5 * 2-7 = - 6 + 25-7 = 12
When n = 3, S3 = - 1.5 * 3 & # 178; + 12.5 * 3-7 = - 13.5 + 37.5-7 = 17
The result is correct

As shown in the figure, use the matchstick to put out a row of square patterns. If you put it down in this way, put out the nth pattern______ A matchstick (expressed in an algebraic expression containing n)

Let the matchstick for the nth pattern be SN. ① graph, S1 = 4; ② graph, S2 = 4 + 3 × 4 - (1 + 3) = 4 + 2 × 4 = 4 (1 + 2); ③ graph, S3 = 4 (1 + 2) + 5 × 4 - (3 + 5) = 4 (1 + 2 + 3) The nth pattern, Sn = 4 (1 + 2 + 3 +...) +n-1）+（2n-1）×4-（2n-3+2n-1）=4（1+2+3+… +n...

How can six matches make four equilateral triangles

With space graphics,
Just form a regular tetrahedron
Three matches form an equilateral triangle,
In addition, one end of the three matches coincides with the vertex of the triangle,
The other three endpoints coincide with another point

Six matches make four equilateral triangles

First take three pieces to make an equilateral triangle, then take the fourth one, put the middle point on the top of the equilateral triangle, and make it parallel to the bottom of the equilateral triangle, take the fifth and sixth matches, connect the end of the fourth match with the middle point of the bottom of the equilateral triangle, and get four small equilateral triangles

How to make four equilateral triangles with six matchsticks of the same length and thickness?

If you put it into a regular triangular pyramid, there will be four equilateral triangles

How to make a square with eight matchsticks into a figure with half its area (the new figure also needs eight matchsticks) Please explain clearly what the figure is Use a few at the top and a few at the bottom